The experiment established that at temperature. Solving problems of the Unified State Exam Part C: Real liquids and gases, solids

1 – The figure shows a graph of the projection v x speed of the car versus time t. Which graph correctly represents the projection of the acceleration of the car in the interval from time 4 s to time 6 s?

2 – The figure shows the trajectory of a body thrown at a certain angle to horizontal surface Earth. At point A of this trajectory, the direction of the velocity vector is indicated by arrow 1; the trajectory of the body and all vectors lie in a plane perpendicular to the surface of the Earth. Air resistance is negligible. What direction does the body's acceleration vector have in the Earth's reference frame? In your answer, indicate the number of the corresponding arrow.

3 – A person weighing 50 kg jumps from a stationary boat weighing 100 kg onto the shore with a horizontal speed of 3 m/s relative to the boat. At what speed does the boat move relative to the Earth after a person jumps, if the resistance of the water to the movement of the boat is negligible?

Answer: _____ m/s

4 – What is the weight of a person in water, taking into account the Archimedes force? Human volume V = 50 dm 3, human body density 1036 kg/m 3.

Answer: _____ H

5 – In the experiment, a graph of the dependence of the velocity modulus of a rectilinearly moving body on time was obtained. Analyzing the graph, choose three correct statements from the statements below and indicate their numbers.

1 – The speed of the body changed from 0 m/s to 6 m/s in 6 seconds.

2 – The body moved uniformly accelerated during the first 6 seconds and did not move in the interval from 6 to 7 seconds.

3 – The body moved equally slowly during the first 6 seconds and did not move in the interval from 6 to 7 seconds.

4 – In a time interval of 4-6 seconds, the speed increased in direct proportion to the time of movement, the body moved with constant acceleration.

5 – The acceleration of the body in the fifth second of movement is 1.5 m/s2.

6 – A weight of mass 2 kg is suspended on a thin cord 5 m long. If it is tilted from its equilibrium position and then released, it makes free vibrations like a mathematical pendulum. What will happen to the period of oscillation of the weight, the maximum potential energy of the weight and the frequency of its oscillation if the initial deflection of the weight is changed from 10 cm to 20 cm?

1 – will increase

2 – will decrease

3 – will not change

Write down the selected numbers for each physical quantity in the table. The numbers in the answer may be repeated.

7 – Material point moves with speed uniformly, rectilinearly and co-directionally with the OX coordinate axis. Match between physical quantities and formulas by which they can be calculated. For each position in the first column, select the corresponding position in the second and write down the selected numbers in the table under the corresponding letters.

8 – The graph shows how the temperature of 0.1 kg of water in starting moment in a crystalline state at a temperature of -100 0 C, at constant power heat transfer 100 W.

Using the graph in the figure, determine how long the internal energy of water increased.

Solution

The graph shows that the temperature of the ice continuously increased and after 210 s it reached 0 0 C. Consequently, the kinetic energy of the ice molecules increased.

Then 333 an amount of heat of 100 J was transferred from the ice every second, but the temperature of the melting ice and the resulting water did not change. The amount of heat received from the heater within 333 s of 33300 J caused the complete melting of the ice. This energy is spent on breaking strong ties water molecules in a crystal, by increasing the distance between molecules, i.e. to increase the potential energy of their interaction.

After all the ice had melted, the process of heating the water began. The water temperature increased by 100 0 C in 418 s, i.e. the kinetic energy of water has increased.

Since the internal energy is equal to the sum of the kinetic energy of all molecules and the potential energy of their interaction, the conclusion follows that the internal energy of water increased throughout the experiment for 961 s.

Answer: 961 s

9 – Ideal gas in some process shown on the graph, 300 J of work was done. How much heat was transferred to the gas?

Answer: _____ J

10 – In a closed room at an air temperature of 40 °C, condensation of water vapor on the wall of a glass of water begins when the water in the glass cools to 16 °C.

What will be the dew point in this room if all the air in the room is cooled to 20 °C?

Answer: _____ °C

11 – Opposite electric charges attract each other due to the fact that

1 – one electric charge is capable of instantly acting on any other electric charge at any distance

2 – around each electric charge there is an electric field that can act on electric fields other charges

3 – around each electric charge there is an electric field that can act on other electric charges

4 – there is gravitational interaction

Which of the above statements is true?

Answer: _____

Solution :

Opposite electric charges are attracted to each other due to the fact that around each electric charge there is an electric field that can act on other electric charges.

Answer: 3

12 – V physical experiment within a few seconds, the movement of the body was recorded on a horizontal and straight section of the path from a state of rest. Based on the experimental data, graphs (A and B) of the time dependence of two physical quantities were constructed.

Which physical quantities listed in the right column correspond to graphs A and B?

For each position in the left column, select the corresponding position in the right column and write down the selected numbers in the table under the corresponding letters.

Answer: _____

Solution :

On the horizontal section of the path, the position of the center of mass of the body does not change, therefore, the potential energy of the body remains unchanged. Answer 4 is excluded from the correct ones.

Answer 2 is excluded from the correct ones, because acceleration at uniformly accelerated motion– constant value.

With uniformly accelerated motion from a state of rest, the path is calculated using the formula s= a* t 2 /2 . This dependence corresponds to graph B.

Speed during uniformly accelerated motion from a state of rest is calculated by the formula v= a* t. This dependence corresponds to graph A.

Answer: 13

13 – Positively charged particle A moves perpendicular to the plane of the picture in the direction towards the observer. Point B is in the drawing plane. How is the induction vector directed at point B (up, down, left, right, from the observer, to the observer) magnetic field, created by a moving particle A? write the answer in word(s).

Answer: _____

Solution :

If we consider the movement of a positively charged particle as an electric current in a conductor, which is located perpendicular to the plane of the figure, then the gimlet (right screw) is directed along the current, and the rotation of the gimlet in relation to the observer will be counterclockwise. In this case, the magnetic induction lines will be directed counterclockwise. Since the vector of magnetic induction of the magnetic field electric current coincides with the tangent to the magnetic induction line, then the induction vector at point B is directed upward.

Answer: up

14 – What is the voltage on the circuit section AB (see figure) if the current through a resistor with a resistance of 2 Ohms is 2 A?

15 – The location of the flat mirror MN and the light source S is shown in the figure. What is the distance from the source S to its image in the mirror MN?

The arrangement of the plane mirror MN and the light source S is shown in the figure. What is the distance from the source S to its image in the mirror MN?

Answer:_____

Solution :

Image of the light source in flat mirror located symmetrically relative to the mirror plane. Therefore, the image in the mirror is exactly the same distance from the plane of the mirror as the light source is located.

Answer: 4 m

The graphs show the results experimental research dependence of the current on the voltage at the ends of the thread electric lamp and the resistance of the lamp filament on current strength.

Analyzing the data, answer the question: what happened to the lamp in this experiment? Select two statements below that correspond to the results of the experimental study.

1 – The lamp filament was heated by the flowing current, an increase in the temperature of the metal filament led to a decrease in its electrical resistivity and an increase in the resistance R of the lamp filament - graph R(I).

2 – The lamp filament was heated by the flowing current, an increase in the temperature of the metal filament led to an increase in its electrical resistivity and an increase in the resistance R of the lamp filament - graph R(I).

3 – The nonlinearity of the I(U) and R(I) dependencies is explained too large error measurements.

4 – The results obtained contradict Ohm’s law for a section of the chain.

5 – As the resistance of the lamp filament increases, the current through the lamp filament decreases - the I(U) dependence.

Answer: _____

Solution :

The lamp filament was heated by electric current. As the temperature of the metal increases, it resistivity growing. Consequently, the resistance of the lamp filament increases. This leads to a decrease in current through the lamp filament.

Answer: 25

17 – To the source direct current one electric lamp was connected, the electrical resistance of which is equal to the internal resistance of the current source. What will happen to the current strength in the circuit, the voltage at the output of the current source and the current power in the external circuit when a second similar lamp is connected in series with this lamp?

For each quantity, determine the corresponding nature of the change:

1 – increase

2 – decrease

3 – immutability

Write down the selected numbers for each physical quantity in the table. Numbers may be repeated.

18 – Graphs A and B show the dependence of some physical quantities on other physical quantities. Establish a correspondence between graphs A and B and the types of dependence listed below. Write down the selected numbers in the table under the corresponding letters.

1 – dependence of the number of radioactive nuclei on time

2 – dependence of stress on relative elongation

3 – dependence of the specific binding energy of nucleons in atomic nuclei on the mass number of the nucleus

4 – dependence of the magnetic field induction in a substance on the magnetizing field induction.

Solution :

Graph A shows the dependence of the number of radioactive nuclei on time (the law of radioactive decay).

Graph B shows the dependence of the specific binding energy of nucleons in atomic nuclei on the mass number of the nucleus.

Answer: 13

19 – As a result of a series of radioactive decays, U-238 turns into lead Pb-206. How many α-decays and β-decays does it experience?

Answer: _____

Solution :

With each -decay, the charge of the nucleus decreases by 2, and its mass decreases by 4. With β-decay, the charge of the nucleus increases by 1, and the mass remains virtually unchanged. Let's write down the equations:

82=(92-2nα)+nβ

From the first equation: 4nα=32, the number of α-decays is 8.

From the second equation: 82=(92-16)+nβ=76+nβ,

82-76=nβ, 6=nβ, number of β-decays 6.

Answer: 8 6

20 – When a metal plate is illuminated with monochromatic light with frequency ν, a photoelectric effect occurs. The maximum kinetic energy of released electrons is 2 eV. What is the value of the maximum kinetic energy of photoelectrons when this plate is illuminated with monochromatic light with a frequency of 2ν?

Answer: _____ eV

21 – When the piston moves very slowly in the cylinder of a closed air pump, the volume of air decreases. How do the pressure, temperature and internal energy of the air change? For each value, determine the corresponding nature of the change:

1 – increases

2 – decreases

3 – does not change

Write down your chosen numbers for each physical quantity. The numbers in the answer may be repeated.

Solution :

When the piston moves very slowly in the cylinder of a closed air pump as a result of heat exchange with environment the air temperature in it does not change. During isothermal compression of a gas, the product of the gas pressure and its volume remains unchanged, therefore, as the volume of air decreases, its pressure increases. At isothermal process internal energy does not change.

Answer: 133

22 – The figure shows a stopwatch, to the right of it is an enlarged image of the scale and arrow. The stopwatch hand makes full turn in 1 minute.

Record the stopwatch readings, taking into account that the measurement error is equal to the value of the stopwatch division.

Answer: (____± ____) s

23 – In the experiment, the task was to determine the acceleration of a block when sliding down inclined plane length l (1).

First, a formula was obtained for calculating acceleration:

Then a detailed drawing was made with the dimensions of the inclined plane a (2), c (3) and the position of the force vectors and their projections.

Friction coefficient value μ (4) the experimenter took the wood from the reference data. Friction force F tr(5) and gravity mg(6) were measured with a dynamometer.

Which of the numbers marked with numbers is enough to use to determine the acceleration of the block?

Solution :

The acceleration can be found by knowing the friction coefficient µ, the dimensions a, s,l inclined plane and calculating the values cosα= c/ l And sinα= a/ l.

Answer: 1234

24 – An ideal gas performed 300 J of work, and at the same time the internal energy of the gas increased by 300 J. How much heat did the gas receive in this process?

25 – A body weighing 2 kg under the influence of force F moves upward on an inclined plane at a distance l = 5 m, the distance of the body from the surface of the Earth increases by h = 3 m. Force F is equal to 30 N. How much work was done by force F during this movement ? Acceleration free fall take equal to 10 m/s 2, friction coefficient μ = 0.5.

Solution :

During the transition from the initial to the final state, the volume of the gas increases, therefore, the gas does work. According to the first law of thermodynamics:

The amount of heat Q transferred to the gas is equal to the amount of change internal energy for and work done by gas:

The internal energy of the gas in states 1 and 3 is expressed in terms of the pressure and volume of the gas:

The work done during the transition of a gas from state 1 to state 3 is equal to:

The amount of heat received by the gas:

A positive Q value means that the gas has received an amount of heat.

30 – When the battery terminals are short-circuited, the current in the circuit is 12 V. When an electric lamp is connected to the battery terminals electrical resistance 5 Ohm, the current in the circuit is 2 A. Based on the results of these experiments, determine the emf of the battery.

Solution :

According to Ohm's law, for a closed circuit, when the battery terminals are short-circuited, the resistance R tends to zero. The current strength in the circuit is equal to:

Hence the internal resistance of the battery is:

When connected to the lamp battery terminals, the current in the circuit is equal to:

From here we get:

31 – A mosquito flies near the surface of the water in the river, a school of fish is at a distance of 2 m from the surface of the water. What is the maximum distance to the mosquitoes at which it is still visible to fish at this depth? The relative refractive index of light at the air-water interface is 1.33.

Option 2

Task B1.

A weight of mass 2 kg is suspended on a thin cord. If it is deflected from the equilibrium position by 10 cm and then released, it performs free oscillations like a mathematical pendulum. What will happen to the period of oscillation of the weight, the maximum potential energy of the weight and the frequency of its oscillations if the initial deflection of the weight is 5 cm?

Since the period mathematical pendulum determined by the formula:

A frequency

That is, if they do not depend on the amplitude of the oscillations, then both the period and frequency of the oscillations will not change.

The potential energy will decrease, because the smaller the amplitude, the lower the height the weight rises -
.

Physical quantities. Their change.

A) period 1) will increase

B) frequency 2) will decrease

B) maximum potential 3) will not change

Task B2.

The stone falls freely vertically downwards. Do the physical quantities listed in the first column change during its downward movement, and if so, how? Establish a correspondence between the physical quantities listed in the first column and possible types their changes listed in the second column. Neglect the influence of resistance.

Physical quantities. Their changes.

A) speed 1) does not change

B) acceleration 2) increases

B) kinetic energy 3) decreases.

D) potential energy

Explanation. The speed of the body when moving downwards increases, since the force of gravity is directed along the movement. The acceleration remains constant because
.

Kinetic energy is determined by the formula
, so the speed also increases. Potential energy is determined by the formula
, therefore decreases. Answer:

Task B3.

The temperature of a small lead ball when falling on a massive steel plate increased by 1 0 C. Neglecting energy losses due to heat transfer to surrounding bodies. Based on the results of this experiment, determine the height from which the ball fell. Specific heat lead 130 J/ (kg∙K). Take the free fall acceleration to be equal to

10 m/s 2. Write your answer as a number expressed in meters.

Since at a height h the body has potential energy, determined by the formula, and the heat required to heat the body
, then according to the law of conservation of energy

From here we get:

Answer: 13m.

Task B4.

Calculate the current in the circuit when connected to a direct current source with an emf of 12 V and an internal resistance of 2 ohms to a resistor with an electrical resistance of 4 ohms. Write your answer as a number expressed in amperes.

According to Ohm's law for complete chain The current strength is determined by the formula:

, we get

Answer: 2A.

Task B5.

The focal length of the collecting lens is 15 cm. At what distance from the lens is an object, the actual image of which was obtained at a distance of 60 cm from the lens? Write down your answer as a number expressed in centimeters.

According to the formula for a thin converging lens, we have:

, from here we get:
, let's substitute the data:

d=20cm

Answer: 20 cm

Task C1.

The experiment established that at an air temperature in the room of 25 0 C on the wall of the glass with cold water Condensation of water vapor from the air begins if the temperature of the glass is reduced to 14 0 C. Based on the results of these experiments, determine the absolute and relative humidity of the air. Use the table to solve the problem. Will the relative humidity change as the air temperature in the room increases if the condensation of water vapor from the air begins at the same glass temperature of 14 0 C. Pressure and density of saturated water vapor at different temperatures.

Relative air humidity is determined by the formula:

where p - partial pressure, P 0 - pressure saturated steam, which at a given temperature is taken from the table. We take the partial pressure in the condition of this problem from the table at the temperature at which steam condensation begins. We get P 0 =3200Pa, p=1600Pa.

Hence the air humidity is:

As the temperature increases, the saturated vapor pressure will increase, but the partial pressure will not change, since condensation occurs at the same temperature. Therefore, the relative humidity will decrease in this case.

Task C2.

In the attraction, a person weighing 60 kg moves on a cart along rails and makes a “dead loop” in a vertical plane along a circular path with a radius of 5 m. What is the force of pressure of a person on the seat of the cart when the speed of passing the bottom point is 10 m/s? Take the acceleration of free pressure equal to 10 m/s 2 .

Solution: let us depict in the drawing the trajectory of movement and the forces acting on a person at the top point:

According to Newton's second law vector sum forces acting on the body is equal to the product of mass and acceleration:

in scalar form this equation looks like:

where F T =mg: from here we find the support reaction force: N=mg+ma. Because centripetal acceleration determined by the formula:
, then we get the formula: N=m (g+v 2 /R).

Let's substitute the data and make calculations: N=60 (10+100/5) =1800H

According to Newton’s third law, the pressure force of a person on the seat is equal in magnitude to the support reaction force, i.e. F d =N, F d =1800H

Answer: 1800N.

Task C3.

The diagram shows changes in pressure and volume of an ideal monatomic

gas How much heat was received or given off by the gas during the transition from state 1 to state 3?

The total amount of heat is determined by the formula:

Q 123 =Q 12 +Q 23

Q 12 =A 12 +ΔU 12’ where A 12 =PΔV=0

ΔU=3/2νRΔT=3/2V 1 (P 2 -P 1)

then the amount of heat in section 1-2 will be equal to:

Q 12 =3/2∙1∙(10-30)= -30kJ.

The amount of heat in section 2-3 will be equal to:

Q 23 =A 23 +ΔU 23; Q 23 = P 2 (V 3 -V 2) + 3/2P 2 (V 3 -V 2) =

5/2P 2 (V 3 -V 2); Q=5/2∙10∙(3-1)=50 kJ,

then the total amount of heat will be equal to: Q=-30+50=20kJ

Heat will be received.

Answer: 20 kJ.

Task C4.

The cathode of a photocell with an output function of 4.42∙10 -19 J is illuminated with light with a frequency

1.0∙10 15 Hz. Electrons emitted from the cathode enter a uniform magnetic field with an induction of 8.3∙10 -4 T perpendicular to the induction lines of this field. What is equal to maximum radius circle R along which electrons move?

According to the law of conservation of energy for the photoelectric effect, we have the formula:

hν =Aout + E k, E k =mv 2 /2, then hν=Aout + mv 2 /2.

From here we determine the speed of the electron:

In a magnetic field, a charged particle is acted upon by the Lorentz force, which is determined by the formula: F=qvBsinα, since the angle is 90 0 C, then sinα=1, then F=qvB.

According to Newton's second law, the force is F=ma.

Equating the two formulas, we obtain the equality: qvB=ma. Acceleration is determined by the formula: a=v 2 /R, from here qvB=m v 2 /R, simplifying, we get:

R = mv/qB, substituting the data, we perform the calculations:

R=9.1∙10 -31 ∙6.92∙10 5 / (1.6∙10 -19 ∙8.3∙10 -4) =4.74∙10 -3 m=4.74mm

Answer: 4.74 mm.

Task C5.

A pool 4 m deep is filled with water, the relative refractive index at the air-water interface is 1.33. What is the depth of the pool to an observer looking vertically down into the water?

According to the law of refraction
, where is the refractive index of water, 1 is the refractive index of air. From triangles ABC and MVS we find leg x: x=h tanβ, x=H∙tgα. Since the left parts are equal, which means the wounds and the right parts, we get the equation: h∙ tgβ= H∙ tgα, hence h= H∙ tgα/ tgβ. We take the angles α and β to be very small, so sinα= tanα, sin β= tanβ. We get equality:

h=H sinα/ sin β =H/n, we get: h=4/1.33=3 m.

Answer: 3 m.

Task C6.

Using mass tables atomic nuclei and elementary particles, calculate the energy released during the synthesis of 1 kg of helium from the isotopes of hydrogen - deuterium and tritium:

Masses of atomic nuclei

Name element	Mass of the atomic nucleus of an isotope
	1, 6726∙10 -27 kg	1, 00727 a. eat.
	3, 3437∙10 -27 kg	2.01355a. eat.
	5.0075∙10 -27 kg	3.01550 a. eat.
	5.0066∙10 -27 kg	3.01493a. eat.
	6.6449∙10 -27 kg	4.00151a. eat.
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Period of a mathematical pendulum. Kinetic and potential energy, specific heat capacity of lead. The current in the circuit when connected to a DC source. Relative air humidity, amount of heat. Photoelectric effect from a metal surface.

Solving problems in physics.

Training Unified State Exam assignments levels "B" and "C" in 2010.

Option 1 Problem No. B1. A weight of mass 2 kg is suspended on a long thin cord. If it is deflected from the equilibrium position by 10 cm and then released, it performs free oscillations like a mathematical pendulum with a period of 1 s. What will happen to the period, the maximum potential energy of the weight and the frequency of its oscillations if the initial deflection of the weight is equal to 20 cm? Solution. Since the period of a mathematical pendulum is determined by the formula:, and the frequency, i.e. do not depend on the amplitude of the oscillations, then both the period and frequency of the oscillations will not change. The potential energy will increase, because the greater the amplitude, the greater the height the weight rises - .Physical quantities. Their change. A) period 1) will increase B) frequency 2) decrease C) maximum potential 3) energy will not change. Answer:

Task No. B2.

A stone is thrown vertically upward. Do the physical quantities listed in the first column change during its upward movement and, if so, how? Neglect the effect of air resistance.

A) speed 1) does not change

B) acceleration 2) increases

D) potential energy

Explanation. The speed of a body when moving upward decreases, since the force of gravity is directed opposite to the movement. The acceleration remains constant because

Kinetic energy is determined by the formula, therefore, the speed decreases as well.

Potential energy is determined by the formula, so it increases.

Task B3.

The temperature of a small lead ball, when dropped onto a massive steel plate from a height of 6.5 m, increased by 0.5 0 C. Neglecting energy losses due to heat transfer to surrounding bodies, determine the specific heat of lead from the result of this experiment. Take the free fall acceleration to be 10 m/s 2 .

Since at a height h the body has potential energy, determined by the formula, and heat is used to heat the body, then according to the law of conservation of energy, we obtain:

Answer: 130 J/kg K.

Task B4.

Calculate the current in the circuit when connected to a direct current source with an emf of 6 V and an internal resistance of 1 ohm to a resistor with an electrical resistance of 2 ohms. Write your answer as a number expressed in amperes.

We get

Answer: 2A.

Task B5.

The focal length of the collecting lens is 15 cm. At what distance from the lens is the image of an object located at a distance of 20 cm from the lens? Write down your answer as a number expressed in centimeters.

Answer: 60 cm

Task C1.

The experiment established that when the air temperature in the room is 23 0 C, condensation of water vapor from the air begins on the wall of a glass with cold water if the temperature of the glass is reduced to 12 0 C. Based on the results of these experiments, determine the absolute and relative humidity of the air. Use the table to solve the problem. Explain why condensation of water vapor in the air can begin when different meanings temperature. Pressure and density of saturated water vapor at different temperatures.

Relative air humidity is determined by the formula: %, where p is the partial pressure, P 0 is the saturated vapor pressure, which at a given temperature is taken from the table. We take the partial pressure in the condition of this problem from the table at the temperature at which steam condensation begins. We get P 0 =3200Pa, p=1400Pa.

Absolute air humidity is equal to the vapor density at a given temperature, i.e. 20.6 g/m 3, or can be considered equal to the partial pressure at this temperature, which is equal to the saturated vapor pressure at the condensation temperature. Condensation of water vapor in the air can begin when different meanings temperatures because relative humidity varies. At higher relative humidity, the concentration of water vapor in the air is greater, so at a higher temperature this water vapor will become saturated, i.e. Condensation will begin at a higher temperature than when the relative humidity is lower.

Task C2.

In the attraction, a person weighing 70 kg moves on a cart along rails and makes a “dead loop” in a vertical plane. At what speed does the cart move at the top point of a circular trajectory with a radius of 5 m, if at this point the force of pressure of a person on the seat of the cart is 700 N? Take the acceleration of free pressure equal to 10 m/s 2 . Solution: let us depict in the drawing the trajectory of movement and the forces acting on a person at the top point: According to Newton’s second law, the vector sum of the forces acting on the body is equal to the product of mass and acceleration:

IN scalar form this equation looks like:

Where F T =mg: from here we find the acceleration:

Since centripetal acceleration is determined by the formula: , we obtain the speed formula:

Answer: 10m/s.

Task C3.

The diagram shows the changes in pressure and volume of an ideal monatomic gas. How much heat was received or given off by the gas during the transition from state 1 to state 3?

Q 123 =Q 12 +Q 23

Q 12 =A 12 +ДU 12" where A 12 =РДV=P 1 (V 2 -V 1),

then the total amount of heat will be equal to: Q 123 =50+90=140 kJ. Heat will be received.

Answer: 140 kJ.

Task C4.

When the battery terminals are short-circuited, the current in the circuit is equal to I 1 = 12 A.

When connecting an electric lamp with an electrical resistance of 5 Ohms to the battery terminals, the current in the circuit is equal to I 2 = 2A. Based on the results of these experiments, determine the emf of the generator.

According to Ohm's law for a complete circuit in the event of a short circuit, where r is the resistance of the current source. External resistance in this case is 0.

If the external resistance is different from 0, then Ohm’s law for the complete circuit has the form:

Expressing from two equations, we obtain a system of equations:

then the emf of the source will be equal to:

Substituting the data, we get:

Answer: 12V.

Task C5.

A mosquito flies near the surface of the river. A school of fish is located at a distance of 2 m from the surface of the water. What is the maximum distance to a mosquito at which it is still visible to fish at this depth? The relative refractive index of light at the air-water interface is 1.33.

Let us depict the location of a school of fish and a mosquito on the surface of the water: At point A there are fish, at point B there is a mosquito. According to the law of refraction, we have the formula: , where is the refractive index of water, for air the refractive index is equal to 1. In order for fish to see a mosquito, the angle of refraction must be equal to 90 0. For the angle by definition of sine we have:

Then to determine the distance r we obtain the formula:

Answer: 2.66m.

Task C6.

Photoeffect from the surface of this metal observed at a radiation frequency of at least 6 10 14 Hz. Find the frequency of the incident light if photoelectrons emitted from the metal surface are completely blocked by a grid whose potential relative to the metal is 3 V.

According to the law of conservation of energy for the photoelectric effect, in the case of light incident with a frequency corresponding to the red boundary of the photoelectric effect and for a higher frequency, we obtain two equations:

Since the work done by an electric current to move a charged particle is equal to the change in the kinetic energy of this particle, i.e.

we obtain the second equation for the photoelectric effect in the form:

Subtracting the first from the second equation, we get:

Let's substitute the data and perform the calculations:

Answer: 1.3 10 15 Hz.

Option 2 Problem B1. A weight of 2 kg is suspended on a thin cord. If it is deflected from the equilibrium position by 10 cm and then released, it performs free oscillations like a mathematical pendulum. What will happen to the period of oscillation of the weight, the maximum potential energy of the weight and the frequency of its oscillations if the initial deflection of the weight is 5 cm? Solution. Since the period of a mathematical pendulum is determined by the formula:, and frequency T. That is, do not depend on the amplitude of the oscillations, then both the period and frequency of the oscillations will not change. The potential energy will decrease, because the smaller the amplitude, the lower the height the weight rises - Physical quantities. Their change. A) period 1) will increase B) frequency 2) decrease C) maximum potential 3) energy will not change. Answer:

Task B2.

The stone falls freely vertically downwards. Do the physical quantities listed in the first column change during its downward movement, and if so, how? Establish a correspondence between the physical quantities listed in the first column and the possible types of their changes listed in the second column. Neglect the influence of resistance.

Physical quantities. Their changes.

A) speed 1) does not change

B) acceleration 2) increases

B) kinetic energy 3) decreases.

D) potential energy

Explanation. The speed of the body when moving downwards increases, since the force of gravity is directed along the movement. The acceleration remains constant because...

Kinetic energy is determined by the formula, therefore, as well as speed, it increases. Potential energy is determined by the formula, so it decreases. Answer:

Task B3.

The temperature of a small lead ball when falling on a massive steel plate increased by 1 0 C. Neglecting energy losses due to heat transfer to surrounding bodies. Based on the results of this experiment, determine the height from which the ball fell. The specific heat capacity of lead is 130 J/(kg K). Take the free fall acceleration to be equal to

10 m/s 2. Write your answer as a number expressed in meters.

Since at a height h the body has potential energy, determined by the formula, and heat is used to heat the body, then according to the law of conservation of energy

From here we get:

Answer: 13m.

Task B4.

According to Ohm's law for a complete circuit, the current strength is determined by the formula:

We get

Answer: 2A.

Task B5.

According to the formula for a thin converging lens, we have:

From here we get: , substitute the data:

Answer: 20 cm

Task C1.

The experiment established that when the air temperature in the room is 25 0 C, condensation of water vapor from the air begins on the wall of a glass of cold water if the temperature of the glass is reduced to 14 0 C. Based on the results of these experiments, determine the absolute and relative humidity of the air. Use the table to solve the problem. Will the relative humidity change as the air temperature in the room increases if the condensation of water vapor from the air begins at the same glass temperature of 14 0 C. Pressure and density of saturated water vapor at different temperatures.

Relative air humidity is determined by the formula:

where p is the partial pressure, P 0 is the saturated vapor pressure, which at a given temperature is taken from the table. We take the partial pressure in the condition of this problem from the table at the temperature at which steam condensation begins. We get P 0 =3200Pa, p=1600Pa.

Hence the air humidity is:

Task C2.

Solution: let us depict in the drawing the trajectory of movement and the forces acting on a person at the top point:

According to Newton's second law, the vector sum of forces acting on a body is equal to the product of mass and acceleration:

in scalar form this equation looks like:

where F T =mg: from here we find the support reaction force: N=mg+ma. Since centripetal acceleration is determined by the formula: , we obtain the formula: N=m (g+v 2 /R).

Let's substitute the data and make calculations: N=60 (10+100/5) =1800H

According to Newton’s third law, the pressure force of a person on the seat is equal in magnitude to the support reaction force, i.e. F d =N, F d =1800H

Answer: 1800N.

Task C3.

The diagram shows changes in pressure and volume of an ideal monatomic

gas How much heat was received or given off by the gas during the transition from state 1 to state 3?

The total amount of heat is determined by the formula:

Q 123 =Q 12 +Q 23

Q 12 =A 12 +ДU 12" where A 12 =РДV=0

DU=3/2nRDT=3/2V 1 (P 2 -P 1)

then the amount of heat in section 1-2 will be equal to:

Q 12 =3/2 1 (10-30)= -30 kJ.

The amount of heat in section 2-3 will be equal to:

Q 23 =A 23 +ДU 23; Q 23 = P 2 (V 3 -V 2) + 3/2P 2 (V 3 -V 2) =

5/2P 2 (V 3 -V 2); Q=5/2 10 (3-1)=50 kJ,

then the total amount of heat will be equal to: Q=-30+50=20kJ

Heat will be received.

Answer: 20 kJ.

Task C4.

The cathode of a photocell with an output function of 4.42 10 -19 J is illuminated with light with a frequency

1.0 10 15 Hz. Electrons emitted from the cathode enter a uniform magnetic field with an induction of 8.3 10 -4 T perpendicular to the induction lines of this field. What is the maximum radius of the circle R along which electrons move?

According to the law of conservation of energy for the photoelectric effect, we have the formula:

hn =Aout + E k, E k =mv 2 /2, then hn=Aout + mv 2 /2.

From here we determine the speed of the electron:

In a magnetic field, a charged particle is acted upon by the Lorentz force, which is determined by the formula: F=qvBsinb, since the angle is 90 0 C, then sinb=1, then F=qvB.

According to Newton's second law, the force is F=ma.

Equating the two formulas, we obtain the equality: qvB=ma. Acceleration is determined by the formula: a=v 2 /R, from here qvB=m v 2 /R, simplifying, we get:

R = mv/qB, substituting the data, we perform the calculations:

R=9.1 10 -31 6.92 10 5 / (1.6 10 -19 8.3 10 -4) =4.74 10 -3 m=4.74mm

Answer: 4.74 mm.

Task C5.

The pool is 4 m deep and filled with water, relative indicator refraction at the air-water interface 1.33. What is the depth of the pool to an observer looking vertically down into the water?

According to the law of refraction, where is the refractive index of water, 1 is the refractive index of air. From triangles ABC and MVS we find leg x: x=h tgв, x=H tgb. Since the left parts are equal, which means the wounds and the right parts, we get the equation: h tgв = H tgб, hence h = H tgб/ tgв. We take angles b and c to be very small, so sinb = tgb, sin c = tgb. We get equality:

h=H sinb/ sin c =H/n, we get: h=4/1.33=3 m.

Answer: 3 m.

Task C6.

Using tables of masses of atomic nuclei and elementary particles, calculate the energy released during the synthesis of 1 kg of helium from the isotopes of hydrogen - deuterium and tritium:

Masses of atomic nuclei

Name element	Mass of the atomic nucleus of an isotope
	1, 6726 10 -27 kg	1, 00727 a. eat.
	3, 3437 10 -27 kg	2.01355a. eat.
	5, 0075 10 -27 kg	3.01550 a. eat.
	5.0066 10 -27 kg	3.01493a. eat.
	6.6449 10 -27 kg	4.00151a. eat.
Aluminum	44.7937 10 -27 kg	26.97441 a. eat.
aluminum	49.7683 10 -27 kg	29.97008a. eat.

Let's find the energy that is released during the fusion of one nucleus using the formula: , where is the mass difference between the masses that enter into the reaction and the masses obtained as a result of the reaction, c is the speed of light in vacuum, c = 3 10 8 m/s.

The number of nuclei contained in a mass of 1 kg of helium can be found using the formula:

Then total energy will be equal to: E=E 1 N; Let's substitute the data and perform the calculations:

E=1.5 10 26 0.2817 10 -11 =4.2 10 14 J

Answer: 4.2 10 14 J

Literature 1. O.F. Kabardin, S.I. Kabardina "Typical" test tasks", Publishing House "Exam" Moscow 2010. 2. Yu. G. Pavlenko "Principles of Physics", textbook, Publishing House "Exam", Moscow 2005. 3. G. Ya. Myakishev, B. B. Bukhovtsev "Physics, 11th grade" , Moscow 2009 Publishing house "Prosveshcheniye".

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Solving problems in physics.

Training tasks Unified State Exam level"B" and "C" in 2010.

Option 1

Task No. B1.

A weight of mass 2 kg is suspended on a long thin cord. If it is deflected from the equilibrium position by 10 cm and then released, it performs free oscillations like a mathematical pendulum with a period of 1 s. What will happen to the period, the maximum potential energy of the weight and the frequency of its oscillations if the initial deflection of the weight is 20 cm?

A frequency

Those. do not depend on the amplitude of the oscillations, then both the period and frequency of the oscillations will not change.

The potential energy will increase, because the greater the amplitude, the greater the height the weight rises -.

A) period 1) will increase

B) frequency 2) will decrease

B) maximum potential 3) energy will not change.

A	B	IN
3	3	1

Task No. B2.

A stone is thrown vertically upward. Do the physical quantities listed in the first column change during its upward movement and, if so, how? Neglect the effect of air resistance.

A) speed 1) does not change

B) acceleration 2) increases

D) potential energy

Explanation. The speed of a body when moving upward decreases, since the force of gravity is directed opposite to the movement. The acceleration remains constant because

Kinetic energy is determined by the formula, therefore, like speed, it decreases.

Potential energy is determined by the formula and therefore increases.

A	B	IN	G
3	1	3	2

Task B3.

From here we get:

Answer: 130 J/kg K.

Task B4.

We get

Answer: 2A.

Task B5.

1/60; f=60cm

Answer: 60 cm

Task C1.

The experiment established that when the air temperature in the room is 23 0 C, condensation of water vapor from the air begins on the wall of a glass with cold water if the temperature of the glass is reduced to 12 0 C. Based on the results of these experiments, determine the absolute and relative humidity of the air. Use the table to solve the problem. Explain why condensation of water vapor in the air can begin at different temperatures. Pressure and density of saturated water vapor at different temperatures.

t 0 C	7	9	11	12	13	14	15	16
PgPa	10	11	13	14	15	16	17	18
ρ g/m 3	7,7	8,8	10,0	10,7	11,4	12,11	12,8	13,6
t 0 C	19	21	23	25	27	29	40	60
P hPa	22	25	28	32	36	40	74	200
ρ g/m 3	16,3	18,4	20,6	23	25,8	28,7	51,2	130,5

Absolute air humidity is equal to the vapor density at a given temperature, i.e. 20.6 g/m 3, or can be considered equal to the partial pressure at this temperature, which is equal to the saturated vapor pressure at the condensation temperature. Condensation of water vapor in the air can begin at different temperatures due to the fact that relative humidity varies. At higher relative humidity, the concentration of water vapor in the air is greater, so at a higher temperature this water vapor will become saturated, i.e. Condensation will begin at a higher temperature than when the relative humidity is lower.

Task C2.

In scalar form this equation looks like:

Where F T =mg: from here we find the acceleration:

Since centripetal acceleration is determined by the formula: , we obtain the speed formula:

Answer: 10m/s.

Task C3.

The diagram shows the changes in pressure and volume of an ideal monatomic gas. How much heat was received or given off by the gas during the transition from state 1 to state 3?

Q 123 =Q 12 +Q 23

Q 12 =A 12 +ΔU 12’ where A 12 =PΔV=P 1 (V 2 –V 1),

then the total amount of heat will be equal to: Q 123 =50+90=140 kJ. Heat will be received.

Answer: 140 kJ.

Task C4.

When the battery terminals are short-circuited, the current in the circuit is equal to I 1 = 12 A.

According to Ohm's law for a complete circuit in the event of a short circuit, where r is the resistance of the current source. External resistance in this case is 0.

If the external resistance is different from 0, then Ohm’s law for the complete circuit has the form:

Expressing from two equations, we obtain a system of equations:

then the emf of the source will be equal to:

Substituting the data, we get:

. Answer: 12V.

Task C5.

Then to determine the distance r we obtain the formula:

Answer: 2.66m.

Task C6.

The photoelectric effect from the surface of this metal is observed at a radiation frequency of at least 6∙10 14 Hz. Find the frequency of the incident light if photoelectrons emitted from the metal surface are completely blocked by a grid whose potential relative to the metal is 3 V.

, (1) and . (2)

Since the work done by an electric current to move a charged particle is equal to the change in the kinetic energy of this particle, i.e.

we obtain the second equation for the photoelectric effect in the form:

. (2)

Subtracting the first from the second equation, we get:

Let's substitute the data and perform the calculations:

Answer: 1.3∙10 15 Hz.

Option 2

Task B1.

Since the period of a mathematical pendulum is determined by the formula:

A frequency

That is, if they do not depend on the amplitude of the oscillations, then both the period and frequency of the oscillations will not change.

The potential energy will decrease, because the smaller the amplitude, the lower the height the weight rises - .

Physical quantities. Their change.

A) period 1) will increase

B) frequency 2) will decrease

B) maximum potential 3) will not change

A	B	IN
3	3	2

Task B2.

The stone falls freely vertically downwards. Do the physical quantities listed in the first column change during its downward movement, and if so, how? Establish a correspondence between the physical quantities listed in the first column and the possible types of their changes listed in the second column. Neglect the influence of resistance.

Physical quantities. Their changes.

A) speed 1) does not change

B) acceleration 2) increases

B) kinetic energy 3) decreases.

D) potential energy

Explanation. The speed of the body when moving downwards increases, since the force of gravity is directed along the movement. The acceleration remains constant because .

Kinetic energy is determined by the formula, therefore, as well as speed, it increases. Potential energy is determined by the formula and therefore decreases. Answer:

A	B	IN	G
2	1	2	3

Task B3.

The temperature of a small lead ball when falling on a massive steel plate increased by 1 0 C. Neglecting energy losses due to heat transfer to surrounding bodies. Based on the results of this experiment, determine the height from which the ball fell. The specific heat capacity of lead is 130 J/ (kg∙K). Take the free fall acceleration to be equal to

10 m/s 2. Write your answer as a number expressed in meters.

Since at a height h the body has potential energy, determined by the formula, and heat is used to heat the body, then according to the law of conservation of energy

From here we get:

Answer: 13m.

Task B4.

According to Ohm's law for a complete circuit, the current strength is determined by the formula:

We get

Answer: 2A.

Task B5.

According to the formula for a thin converging lens, we have:

From here we get: , substitute the data:

d=20cm

Answer: 20 cm

Task C1.

t 0 C	7	9	11	12	13	14	15	16
PgPa	10	11	13	14	15	16	17	18
ρ g/m 3	7,7	8,8	10,0	10,7	11,4	12,11	12,8	13,6
t 0 C	19	21	23	25	27	29	40	60
P hPa	22	25	28	32	36	40	74	200
ρ g/m 3	16,3	18,4	20,6	23	25,8	28,7	51,2	130,5

Relative air humidity is determined by the formula:

Hence the air humidity is:

Task C2.

Solution: let us depict in the drawing the trajectory of movement and the forces acting on a person at the top point:

According to Newton's second law, the vector sum of forces acting on a body is equal to the product of mass and acceleration:

in scalar form this equation looks like:

where F T =mg: from here we find the support reaction force: N=mg+ma. Since centripetal acceleration is determined by the formula: , we obtain the formula: N=m (g+v 2 /R).

Let's substitute the data and make calculations: N=60 (10+100/5) =1800H

According to Newton’s third law, the pressure force of a person on the seat is equal in magnitude to the support reaction force, i.e. F d =N, F d =1800H

Answer: 1800N.

Task C3.

The diagram shows changes in pressure and volume of an ideal monatomic

gas How much heat was received or given off by the gas during the transition from state 1 to state 3?

The total amount of heat is determined by the formula:

Q 123 =Q 12 +Q 23

Q 12 =A 12 +ΔU 12’ where A 12 =PΔV=0

ΔU=3/2νRΔT=3/2V 1 (P 2 -P 1)

then the amount of heat in section 1-2 will be equal to:

Q 12 =3/2∙1∙(10-30)= -30kJ.

The amount of heat in section 2-3 will be equal to:

Q 23 =A 23 +ΔU 23; Q 23 = P 2 (V 3 -V 2) + 3/2P 2 (V 3 -V 2) =

5/2P 2 (V 3 -V 2); Q=5/2∙10∙(3-1)=50 kJ,

then the total amount of heat will be equal to: Q=-30+50=20kJ

Heat will be received.

Answer: 20 kJ.

Task C4.

The cathode of a photocell with an output function of 4.42∙10 -19 J is illuminated with light with a frequency

1.0∙10 15 Hz. Electrons emitted from the cathode enter a uniform magnetic field with an induction of 8.3∙10 -4 T perpendicular to the induction lines of this field. What is the maximum radius of the circle R along which electrons move?

According to the law of conservation of energy for the photoelectric effect, we have the formula:

hν=Aout + E k, E k =mv 2 /2, then hν=Aout + mv 2 /2.

From here we determine the speed of the electron:

In a magnetic field, a charged particle is acted upon by the Lorentz force, which is determined by the formula: F=qvBsinα, since the angle is 90 0 C, then sinα=1, then F=qvB.

According to Newton's second law, the force is F=ma.

Equating the two formulas, we obtain the equality: qvB=ma. Acceleration is determined by the formula: a=v 2 /R, from here qvB=mv 2 /R, simplifying, we get:

R = mv/qB, substituting the data, we perform the calculations:

R=9.1∙10 -31 ∙6.92∙10 5 / (1.6∙10 -19 ∙8.3∙10 -4) =4.74∙10 -3 m=4.74mm

Answer: 4.74 mm.

Task C5.

A pool 4 m deep is filled with water, the relative refractive index at the air-water interface is 1.33. What is the depth of the pool to an observer looking vertically down into the water?

According to the law of refraction, where is the refractive index of water, 1 is the refractive index of air. From triangles ABC and MVS we find side x: x=htgβ, x=H∙tgα. Since the left parts are equal, which means the wounds and the right parts, we get the equation: h∙ tgβ= H∙ tgα, hence h= H∙ tgα/ tgβ. We take the angles α and β to be very small, so sinα= tanα, sinβ= tanβ. We get equality:

h=H sinα/ sin β =H/n, we get: h=4/1.33=3 m.

Answer: 3 m.

Task C6.

Using tables of masses of atomic nuclei and elementary particles, calculate the energy released during the synthesis of 1 kg of helium from the isotopes of hydrogen - deuterium and tritium:

Masses of atomic nuclei

The number of nuclei contained in a mass of 1 kg of helium can be found using the formula:

Then the total energy will be equal to: E=E 1 ∙N; Let's substitute the data and perform the calculations:

E=1.5∙10 26 ∙0.2817∙10 -11 =4.2∙10 14 J

Answer: 4.2∙10 14 J

Literature

1. O.F. Kabardin, S.I. Kabardina "Typical test tasks", Publishing House "Exam" Moscow 2010.

2. Yu.G. Pavlenko "Principles of Physics", textbook, Publishing House "Exam", Moscow 2005.

3. G.Ya. Myakishev, B.B. Bukhovtsev "Physics, 11th grade", Moscow 2009. Publishing house "Prosveshcheniye".

A little water was poured into a glass flask and closed with a stopper. The water gradually evaporated. At the end of the process, only a few drops of water remained on the walls of the flask. The figure shows a graph of concentration versus time n molecules of water vapor inside the flask. Which statement can be considered correct?

o 1) in section 1 the steam is saturated, and in section 2 it is unsaturated

o 2) in section 1 the steam is unsaturated, and in section 2 it is saturated

o 3) in both areas the steam is saturated

2. Task No. D3360E

Relative humidity in a closed vessel is 60%. What will the relative humidity be if the volume of the vessel at a constant temperature is reduced by 1.5 times?

5. Task No. 4aa3e9

Relative humidity in the room at a temperature of 20 ° C
equal to 70%. Using the pressure table saturated vapors water, determine the water vapor pressure in the room.

o 1)21.1 mm Hg. Art.

o 2)25 mm Hg. Art.

o 3)17.5 mmHg. Art.

o 4)12.25 mm Hg. Art.

32. Task No. e430b9

The relative humidity in the room at a temperature of 20°C is 70%. Using the table of density of saturated water vapor, determine the mass of water in cubic meter premises.

o 3)1.73⋅10 -2 kg

o 4)1.21⋅10 -2 kg

33. Task No. DFF058

In the figure there are pictures: dotted line - graph of saturated vapor pressure water from the temperature, and a continuous line - process 1-2 due to the change in steam pressure water.

As the water vapor pressure changes, the absolute humidity of the air

1) increase

2) decreases

3) not from me

4) can either increase or decrease

34. Task No. e430b9

To determine the relative humidity of the air, they use the difference between dry and moist thermometer (see ri-su-nok). Using the given ri-sun-ka and the psi-chro-met-ri-che-table, determine what temperature ( in cities Celsius) is called a dry thermometer if the relative humidity of the air in the room -NII 60%.

35. Task No. DFF034

In the co-su-de, under the piston, there is unsaturated steam. It can be re-ve-sti-tied,

1) iso-bar-but-high-temp-pe-ra-tu-ru

2) adding another gas to the vessel

3) increase the volume of steam

4) reducing the volume of steam

36. Task No. 9C5165

The relative humidity in the room is 40%. How-to-work-out-of-concentration n mo-le-kul of water in the air of the room and the concentration of mo-le-kul of water in saturated water vapor at the same temperature per-ra-tu-re?

1) n is 2.5 times less

2) n is 2.5 times larger

3) n is 40% less

4) n 40% more

37. Task No. DFF058

The relative humidity of the air in the cylinder under the piston is 60%. The air iso-ter-mi-che-ski was compressed, reducing its volume by half. The high humidity of the air has become

38. Task No. 1BE1AA

In a closed qi-lin-dri-che-sky so-su-de, there is moist air at a temperature of 100 °C. In order for you to have dew on the walls of this co-su-da, the volume of co-su-da is 25 once. What is the approximation of the initial absolute humidity of the air in the co-su-de? The answer is given in g/m 3, rounded to whole numbers.

39. Task No. 0B1D50

In a cylindrical vessel under the piston long time there are water and its steam. The piston begins to move out of the vessel. At the same time, the temperature of water and steam remains unchanged. How will the mass of liquid in the vessel change? Explain your answer by indicating what physical laws you used to explain

40. Task No. C32A09

Water and its steam are kept in a cylindrical vessel under the piston for a long time. The piston begins to be pushed into the vessel. At the same time, the temperature of water and steam remains unchanged. How will the mass of liquid in the vessel change? Explain your answer by indicating what physical laws you used to explain.

41. Task No. AB4432

In an experiment illustrating the dependence of boiling point on air pressure (Fig. A ), water boiling under the air pump bell occurs already at room temperature, if the pressure is low enough.

Using a pressure plot saturated steam on temperature (Fig. b ), indicate what air pressure needs to be created under the pump bell so that water boils at 40 °C. Explain your answer by indicating what phenomena and patterns you used to explain.


(A)	(b)

42. Task No. E6295D

Relative air humidity at t= 36 o C is 80%. Saturated vapor pressure at this temperature p n = 5945 Pa. What mass of steam is contained in 1 m 3 of this air?

43. Task No. 9C5165

A man with glasses walked into a warm room from the street and discovered that his glasses had fogged up. What must be the outside temperature for this phenomenon to occur? The room temperature is 22°C and the relative humidity is 50%. Explain how you got the answer. (Refer to the table for the vapor pressure of water to answer this question.)

44. Task No. E6295D

In the closed room there is steam and a certain amount of water. How do the following three quantities change with an iso-thermal decrease in volume: giving -le-nie in co-su-de, mass of water, mass of steam? For each ve-li-chi-ny, the definition of co-from-ve-st-st-yu-sha-sha-rak-ter from-me-not:

1) will increase;

2) decrease;

3) not from me.

Write down the selected numbers for each physical size in the table. The numbers in the text may be repeated.

45. Task No. 8BE996

The absolute humidity of the air in the qi-lin-dri-che-su-de-su-de under the piston is equal to . The temperature of the gas in the co-su-de is 100 °C. How and how many times is the iso-ter-mi-che-ski required to change the volume of co-su-da in order for it to form on its walls Was there dew?

1) reduce the sewing by 2 times 2) increase the sewing by 20 times
3) reduce the sewing by 20 times 4) increase the sewing by 2 times

46. Task No. 8BE999

In the ex-pe-ri-men it is established that at the same time the air is in the room on the wall of the st-ka-na with With cold water there is a condensation of water vapor from the air, if you reduce the temperature to . Based on the results of these ex-peri-men, the air humidity is determined. To decide, use the table. Does the relative humidity change when the air temperature in the room increases, if the condensation of water vapor from the air will be at the same temperature? Pressure and density of saturated water steam at different temperatures in the table -face:



7,7	8,8	10,0	10,7	11,4	12,11	12,8	13,6	16,3	18,4	20,6	23,0	25,8	28,7	51,2	130,5

The experiment established that at temperature. Solving problems of the Unified State Exam Part C: Real liquids and gases, solids

Option 2

Physical quantities. Basic Physics

Physical quantities, characterizing fields of ionizing radiation

Morphological features physical development and their importance for selection in sport (2)

Option 1

Option 2

Literature