GIA, State certification in Physics, Option No. 1205, 9th grade, 2012.
For execution exam paper In physics, 3 hours (180 minutes) are allotted. The work consists of 3 parts and includes 25 tasks. Part 1 contains 18 tasks (1–18). For each task there are 4 possible answers, of which only one is correct.
When completing Part 1, circle the number of the selected answer in the exam paper. If you circled the wrong number, cross out the circled number and then circle the number for the correct answer.
Examples.
1. A body is thrown vertically upward relative to the ground. Which of the graphs of the velocity modulus υ versus time t corresponds to upward movement if air resistance can be neglected?
2. A glass vessel, the right elbow of which is sealed, is filled with a liquid of density ρ (see figure). The pressure exerted by the liquid on the bottom of the vessel at point A is equal.
3. When lowered into a glass with hot water wooden and aluminum spoons heat up faster
1) aluminum spoon, since aluminum has a higher density
2) a wooden spoon, since the thermal conductivity of wood is lower
3) aluminum spoon, since the thermal conductivity of aluminum is higher
4) wooden spoon, since wood is less dense
4. Based on the results of heating a body weighing 5 kg, which was initially in a crystalline state, a graph was constructed of the dependence of the temperature of this substance on the amount of heat it received. Assuming that energy losses can be neglected, determine the amount of heat required to heat 1 kg of substance in solid state by 1 °C?
5. Changing electrical voltage on a section of the circuit consisting of a nickel conductor with an area cross section 0.2 mm2, the student recorded the obtained current and voltage measurement data in a table. What is the length of the conductor?
6. During a physics lesson, the teacher demonstrated the following experiments.
A. When free falling from a certain height from a state of rest, a pebble reaches the floor surface faster compared to a feather.
B. In a glass tube with air evacuated, both a pebble and a feather fall simultaneously.
Which experiment(s) allows us to test the hypothesis that the force of resistance from the air depends on the properties of the body?
1) only A
2) only B
3) both A and B
4) neither A nor B
7. A car moves uniformly along a horizontal road. Determine the mass of the car if, to travel 142 km with an average resistance force equal to 0.03 of the car's weight, the car consumed 15 liters of gasoline. The engine efficiency is 20%.
8. An electric kettle with a heating element resistance of 12.1 Ohm contains 0.6 kg of water at 20 °C. The kettle was plugged into a 220 V network and they forgot to turn it off. What is the efficiency of the installation if after 11 minutes the water has completely boiled away?
State (final) certification in PHYSICS
Training option № 1
Instructions for performing the work
3 hours (180 minutes) are allotted to complete the examination work in physics. The work consists of 3 parts and includes 27 tasks.
Part 1 contains 19 tasks (119). For each of the first 18 tasks there are 4 possible answers, of which only one is correct. When completing these tasks in Part 1, circle the number of the selected answer in the exam paper. If you circled the wrong number, cross out the circled number and then circle the number for the correct answer. The answer to task 19 of part 1 is written down on a separate sheet.
Part 2 includes 4 short answer questions (2023). When completing tasks in Part 2, the answer is written down in the exam paper in the space provided. If you write down an incorrect answer, cross it out and write a new one next to it.
Part 3 contains 4 tasks (2427), to which you must give a detailed answer. Answers to tasks in Part 3 are written down on a separate sheet. Task 24 is experimental and requires the use of laboratory equipment.
When making calculations, it is allowed to use a non-programmable calculator.
We advise you to complete the tasks in the order in which they are given.
To save time, skip a task that you cannot complete immediately and move on to the next one. If you have time left after completing all the work, you can return to the missed tasks.
The points you receive for all completed tasks are summed up. Try to complete as much as possible more tasks and dial as much as possible large quantity points.
We wish you success!
Below is reference information that you may need when performing the work.
|
Decimal prefixes |
||
|
Name |
Designation |
Factor |
|
10 9 |
||
|
10 6 |
||
|
10 3 |
||
|
10 2 |
||
|
10 2 |
||
|
10 3 |
||
|
10 6 |
||
|
10 9 |
||
|
Constants |
|
|
acceleration free fall on the ground |
g = 10 |
|
gravitational constant |
G = 6.7·1011 |
|
speed of light in vacuum |
c = 3108 |
|
elementary electric charge |
1.61019 Cl |
|
Density |
|||
|
wood (pine) |
|||
|
machine oil |
aluminum |
||
|
whole milk |
|||
|
sea water |
steel, iron |
||
|
glycerol |
|||
|
Specific |
|||
|
heat capacity of water |
heat of vaporization of water |
2,310 6 |
|
|
heat capacity of alcohol |
heat of vaporization of alcohol |
9,010 5 |
|
|
heat capacity of ice |
melting lead |
2,510 4 |
|
|
heat capacity of aluminum |
melting heat of steel |
7,810 4 |
|
|
heat capacity of steel |
heat of fusion of tin |
5,910 4 |
|
|
heat capacity of zinc |
heat of fusion of ice |
3,310 5 |
|
|
heat capacity of copper |
heat of combustion of alcohol |
2,910 7 |
|
|
heat capacity of tin |
calorific value of kerosene |
4,610 7 |
|
|
heat capacity of lead |
heating value of gasoline |
4,610 7 |
|
|
heat capacity of bronze |
|||
|
Melting temperature |
Boiling temperature |
||
|
Electrical resistivity,(at 20 °C) |
|||
|
nichrome (alloy) |
|||
|
aluminum |
|||
Part 1
For each of the tasks 118 there are 4 possible answers, of which only one is correct. Circle the number of this answer.
1
The figure shows a graph of the projection of acceleration versus time for a body moving rectilinearly along the Ox axis.
ax,
Uniformly accelerated motion corresponds to the plot
2
The figure shows a graph of the velocity modulus of a body weighing 2 kg, moving rectilinearly relative to the Earth, as a function of time.
What is the resultant of the forces acting on the body at a time equal to 3 s?
3
A ball is thrown vertically upward from the surface of the Earth with a speed v. Air resistance is negligible. When the mass of the thrown ball increases by 2 times and other constant conditions, the height of the ball rises
4
The acceleration of gravity near the surface of the Moon is 1.6. It means that
|
after 10 s of free fall from rest, the speed of the body will be 16 |
|
|
in 1 s of movement from a state of rest the body will fly 16 m |
|
|
after 1 s of free fall from rest, the speed of the body will be 16 |
|
|
in 10 s of free fall from rest the body will fly 16 m |
5
A solid cube having density ρк and edge length a was omitted
into a liquid of density ρl as shown in the figure.
The pressure exerted by the liquid on top edge cube, equal
|
ρg (h 2 + a) |
|
|
ρк gh 1 |
|
|
ρк g (h 2 + a) |
|
|
ρж gh 1 |
6
A body of mass 5 kg lies on horizontal surface. The body was once acted upon by a horizontal force of 4 N, and another time by a horizontal force of 12 N. The coefficient of friction between the body and the surface was 0.2. The friction force arising in the second case is
7
Copper and aluminum balls of the same mass were heated by 50 o C. At the same time, it took energy to heat the copper ball
|
more because the density of copper is higher |
|
|
less because the density of copper is less |
|
|
less because the specific heat capacity of copper is less |
|
|
more because the specific heat capacity of copper is greater |
8
Specific heat iron is 500 J/(kg∙deg). What does this mean?
|
When 1 kg of iron is cooled by 10 C, 500 J of energy is released |
|
|
When 500 kg of iron is cooled by 10 C, 1 J of energy is released |
|
|
When 1 kg of iron is cooled at 500 0 C, 1 J of energy is released |
|
|
When 500 kg of iron is cooled by 10 C, 500 J of energy is released |
9
Based on the results of heating a body weighing 5 kg, a graph was drawn up of the dependence of the temperature of this body on the amount of heat it received. Before heating began, the body was in a solid state.
Assuming that energy losses can be neglected, determine the amount of heat required to melt 1 kg of the substance that makes up this body.
10
Two uncharged electrometers are connected by a steel wire. A negatively charged ebonite rod was brought to the first electrometer, without touching it. At the same time, the arrows of the electrometers deviated (see figure), since
|
purchased both electrometers positive charge |
|
|
the first electrometer acquired a positive charge, and the second negative charge |
|
|
the first electrometer acquired a negative charge, and the second one acquired a positive charge |
|
|
both electrometers acquired a negative charge |
11
The ends of copper (1), iron (2) and aluminum (3) conductors of the same size were connected in series and connected to the source DC voltage. Compare the voltages at the ends of each conductor.
iron
|
U 1 > U 2 > U 3 |
U 3 > U 2 > U 1 |
U 2 > U 3 > U 1 |
U 1 > U 3 > U 2 |
12
Electric current flows through the conductor (a graph of current I versus time t is shown in the figure).
There is a magnetic field around the conductor
|
only in the time interval from 0 to t 1 |
|
|
only in the time interval from t 1 to t 2 |
|
|
only in the time interval from t 2 to t 3 |
|
|
in the time interval from 0 to t 1 and from t 2 to t 3 |
13
The height of the Sun above the horizon (see figure) is 50°. What is the angle of incidence of the beam at flat mirror, located at a certain angle to the horizon at point A, if the ray is reflected vertically upward from the mirror?
14
Determine the ammeter reading if the voltmeter shows 6 V.
15
Using fragment Periodic table chemical elements, presented in the figure, determine which particle is accompanied by the emission of the radioactive transformation of the lead-187 nucleus into a nucleus
mercury-183.
200,61
204 , 37
207 , 19
Gold
Mercury
Thallium
Bismuth
Polonium
Astatine
Radon
Lead
16
The student conducted experiments to study rigidity by stretching various wires. He presented the results of measurements of the initial length l 0, cross-sectional area S and calculated stiffness in the table.
|
Material |
l 0, cm |
S, mm2 |
||
Based on the results of the measurements, it can be stated that the wire stiffness
|
decreases as the original length decreases |
|
|
decreases as the cross-sectional area of the wire decreases |
|
|
increases as the original length decreases |
|
|
increases as the cross-sectional area of the wire decreases |
Read the text and complete tasks 1719.
Ultraviolet radiation
Ultraviolet radiation electromagnetic radiation, occupying the range between visible radiation and x-ray radiation. The short-wavelength portion of ultraviolet radiation emitted by the Sun does not reach the Earth's surface. Due to the presence of the ozone layer in the Earth's atmosphere, which absorbs ultra-violet rays, the spectrum of solar radiation near the Earth's surface ends at a wavelength of 290 nm.
The ultraviolet spectrum is divided into ultraviolet-A (UV-A) with a wavelength of 315400 nm, ultraviolet-B (UV-B) 280315 nm and ultraviolet-C (UV-C) 100280 nm, which differ in terms of penetration and biological effects on the body.
UV-A is not delayed ozone layer and passes through the stratum corneum of the skin. Under the influence of ultraviolet light, a special pigment is produced in the skin that intensely reflects this part solar spectrum. In this case, the skin acquires a characteristic shade known as tan. The spectral maximum of pigmentation corresponds to a wavelength of 340 nm. Window glass practically does not transmit ultraviolet rays in the range of 310340 nm and thereby protects the skin from tanning.
Almost all UV-C and approximately 90% of UV-B are absorbed by ozone, as well as water vapor, oxygen and carbon dioxide when passing sunlight through the earth's atmosphere.
On the human body bad influence has both a lack of ultraviolet radiation and its excess. Exposure of the skin to large doses of UV radiation leads to skin diseases. Increased doses of UV radiation also affect the central nervous system. Ultraviolet radiation with a wavelength of less than 0.32 microns negatively affects the retina of the eyes, causing painful inflammatory processes.
The lack of UV rays is dangerous for humans, since these rays are a stimulator of the basic biological processes of the body. The most pronounced manifestation of “ultraviolet deficiency” is vitamin deficiency, in which phosphorus-calcium metabolism and the process of bone formation are disrupted, as well as a decrease in the performance and protective properties of the body from diseases. Such manifestations are typical for the autumn-winter period with a lack of natural ultraviolet radiation (“light starvation”). Ultraviolet radiation with a wavelength of 0.280.2 microns has the ability to kill microorganisms.
17
The term "light fasting" is associated with
|
insufficient lighting in the room |
|
|
lack of ultraviolet radiation with a wavelength of less than 290 nm |
|
|
lack of ultraviolet radiation with a wavelength greater than 290 nm |
18
The figure shows the optical transmission spectra of synthetic quartz glass Suprasil 300, optical glass BK 7 and ordinary window glass.
According to the data presented, it can be argued that
|
Suprasil 300 quartz glass transmits all ultraviolet radiation reaching the Earth's surface |
|
|
all glasses transmit the infrared part of the solar spectrum equally well |
|
|
window glass compared to other glasses in nai to a greater extent misses infrared radiation |
|
|
glasses with optical glasses BK 7 completely protect the eyes from ultraviolet-A (UV-A) |
When completing task 19 with a detailed answer, use a separate sheet. Write down the task number first and then the answer to it. A complete answer should include not only the answer to the question, but also its detailed, logically connected rationale.
19
Part 2
When completing tasks with a short answer (tasks 2023), you must write down the answer in the place indicated in the text of the task.
The answer to each of the tasks 2023 will be a certain sequence of numbers. Enter the numbers numbers of the selected answers in the table at the bottom of the task. Write each number in a separate box. The numbers in the answers to tasks 2021 may be repeated.
20
The load is lifted using a moving block of radius R (see figure). Match between physical quantities and the formulas by which they are determined.
Write down the selected numbers in the table under the corresponding letters.
The numbers in the answer may be repeated.
|
PHYSICAL QUANTITIES |
||||||||||||
|
21
An object located at a distance of 4F from the converging lens is brought closer to the lens at a distance of 2F (F focal length of the lens). How does the optical power of the lens, the size of the image, and the distance from the lens to the image change?
For each physical quantity, determine the corresponding nature of change.
Write down the selected numbers for each physical quantity in the table. The numbers in the answer may be repeated.
|
PHYSICAL QUANTITY |
NATURE OF CHANGE |
|
22
The figure shows graphs of displacement x versus time t for oscillations of two mathematical pendulums. From the proposed list of statements, select two correct ones. Indicate their numbers.
|
When moving pendulum 2 from the position corresponding to point A to the position corresponding to point B, kinetic energy the pendulum increases. |
|
|
Pregnant, corresponding point B on the graph, both pendulums have maximum kinetic energy. |
|
|
The periods of oscillation of pendulums coincide. |
|
|
In the position corresponding to point D on the graph, pendulum 1 has maximum speed. |
|
|
Both pendulums perform damped oscillations. |
23
Poured into two cylindrical vessels equal amount cold and hot water (see picture). As a result of observations, it was noted that the process of evaporation of water occurred in both vessels, but hot water evaporated faster than cold.
Which statements correspond to the results of the studies? experimental measurements?
From the proposed list of statements, select two correct ones. Indicate their numbers.
|
The process of water evaporation can be observed at any temperature. |
|
|
The rate of evaporation of a liquid increases with increasing its temperature. |
|
|
The rate of evaporation of a liquid depends on its surface area. |
|
|
The rate of evaporation of a liquid depends on the type of liquid. |
|
|
In the presence of wind, water evaporates faster. |
Part 3
To answer the tasks of part 3 (tasks 2427), use a separate sheet. Write down the task number first and then the answer to it.
24
In the answer form:
Task 25 is a question that requires a written answer. A complete answer should include not only the answer to the question, but also its detailed, logically connected rationale.
25
For tasks 2627 you need to write down complete solution, including the entry short terms problems (Given), recording formulas, the use of which is necessary and sufficient to solve the problem, as well as mathematical transformations and calculations leading to a numerical answer.
26
27
Assessment system for examination work in physics
Part 1
For correct completion of each of the tasks 118, 1 point is awarded.
|
Job No. |
Answer |
Job No. |
Answer |
Job No. |
Answer |
Part 2
Tasks 20-23 are scored 2 points if all elements of the answer are correctly indicated, 1 point if at least one element of the answer is correctly indicated, and 0 points if the answer does not contain elements of the correct answer.
|
Job No. |
Answer |
Part 3
Criteria for assessing tasks with a detailed answer
19
Which area of ultraviolet radiation is advisable to use to obtain the maximum bactericidal effect? Explain your answer.
Sample possible answer
1. Answer: ultraviolet-C (UV-C).
2. Explanation: Ultraviolet radiation with a wavelength of 0.280.2 microns has the ability to kill microorganisms. Specified lengths waves belong to the interval corresponding to ultraviolet-C (ultraviolet-C is radiation with a wavelength of 100280 nm).
|
Points |
|
|
The correct answer to the question is presented, and sufficient justification is provided without errors. |
|
|
Correct reasoning leading to the correct answer is presented, but the answer is not clearly stated. |
|
|
The answer to the question is incorrect, regardless of whether the reasoning is correct, incorrect, or missing. |
|
|
Maximum score |
24
Using a current source, voltmeter, ammeter, key, rheostat, connecting wires, resistor labeled R 1, assemble an experimental setup to determine the power dissipated by the resistor. Using a rheostat, set the current in the circuit to 0.3 A.
In the answer form:
1) draw electrical diagram experiment;
2) write down the formula for calculating power electric current;
3) indicate the results of measuring voltage at a current of 0.3 A;
4) write down the numerical value of the electric current power.
Equipment characteristics
When performing the task, equipment set No. 5 is used
in the following composition:
|
Laboratory kits |
Set "GIA-laboratory" |
|
Set No. 5 |
|
|
at input voltage (362)V, the emf is (4.20.4)V)
|
Attention! When replacing any piece of equipment with a similar one
with other characteristics, it is necessary to make appropriate changes to the sample assignment.
Sample possible implementation
1. Scheme experimental setup:
2. P = U ·I.
3.I = 0.3 A; U = 3.6 V.
4. P = 1.1 W.
Advice to experts
Numerical value direct voltage measurement should fall within the interval U = (3.6 ± 0.6) V.
For the GIA-laboratory kit, the interval is U = (2.5 ± 0.3) V.
25
Two boats move uniformly across the lake in parallel courses towards each other. The friction of boats on water is negligible. When the boats drew level, they transferred the load from the first boat to the second, carefully releasing it from their hands. Did the speed of the first boat change (if it changed, then how)? Explain your answer.
Sample possible answer
1. The speed of the first boat has not changed.
2. During the time interval when the load is transferred to the second boat, it is not pushed horizontally, i.e. it is not acted upon by horizontal forces. Therefore, no horizontal forces act on the first boat from the side of the load in this time interval. Therefore, the speed of the first boat has not changed.
|
Points |
|
|
The correct answer to the question is presented and sufficient justification is provided without errors |
|
|
The correct answer to the question is presented, but its justification is incorrect or missing. Correct reasoning leading to the correct answer is presented, but the answer is not clearly stated |
|
|
Presented general reasoning, not related to the answer to the question posed. The answer to the question is incorrect regardless of whether the reasoning is correct, incorrect, or missing |
|
|
Maximum score |
26
A bullet weighing 9 g, moving at a speed of 800, pierced a board 2.5 cm thick and had a speed of 200 when exiting the board. Define average strength resistance acting on the bullet in the board.
|
Possible variant solutions |
|
|
Given: 800 m/s 200 m/s m = 9 g = 0.009 kg S = 2.5 cm = 0.0 25 m |
A = Δ E kin A = F∙S F = 108,000 N |
|
F ? |
Answer: F = 108 kN |
|
Points |
|
|
To solve a problem using the chosen method. ( IN this decision equality mechanical work change in kinetic energy; formulas for calculating mechanical work, kinetic energy). |
|
|
the use of which is necessary and sufficient |
|
|
Maximum score |
27
The electric locomotive moves with constant speed 72 and drives a train weighing 1800 tons. The current consumed by the electric locomotive from a 3000 V network is 750 A. The friction coefficient is 0.005. Determine the efficiency of the electric locomotive engine.
|
Points |
|
|
Complete correct solution, including the following elements: 1) the brief statement of the problem is written correctly; 2) equations and formulas are written down, the use of which is necessary and sufficient to solve the problem using the chosen method ( in this solution formula for the coefficient useful action, electric current power formula, formula mechanical power; Newton's second law, friction force formula) 3) the necessary mathematical transformations and calculations leading to the correct numerical answer are performed, and the answer is presented. In this case, a solution is allowed “in parts” (intermediate calculations) |
|
|
Correctly written necessary formulas, calculations were carried out, and an answer was received (true or incorrect), but an error was made in recording the brief condition or converting units to SI. The correct solution is presented only in general view, without any numerical calculations. Equations and formulas are written down, the use of which is necessary and sufficient to solve the problem using the chosen method, but an error was made in the mathematical transformations or calculations |
|
|
Not all initial formulas necessary to solve the problem have been written down and used. All the original formulas are written down, but there is an error in one of them |
|
|
All cases of solution that do not meet the above criteria for scoring 1, 2, 3 points |
|
|
Maximum score |
1. Section "Thermal phenomena"
1.5. Specific heat
1. Specific heat capacity is a physical quantity that shows
1) how much heat must be transferred to the body so that its temperature changes by 1 ° C
2) how much heat can be used to heat a body weighing 1 kg
3) how much heat is required to be transferred to a body weighing 1 kg so that its temperature increases by 1 O C
2. What amount of heat is required to increase the temperature by 1 O C of pieces of tin and copper weighing 1 kg each?
1) 230 J and 400 J
2) 23 J and 40 J
3) 230 J and 40 J
4) 23 J and 400 J
3. Equally heated metal bars equal mass brought into a cold room. Which one will highlight greatest number warmth?
1) №1
2) №2
3) №3
4) There is no necessary data to answer
4. Liquids of equal mass having the same temperature are poured into the vessels: sunflower oil, water and kerosene. Which of them will heat up the least if the same amount of heat is given to them?
1) Oil
2) Water
3) Kerosene
5. Based on heating results crystalline substance weighing 5 kg, a graph was drawn up of the dependence of the temperature of this substance on the amount of heat supplied. 
Assuming that energy losses can be neglected, determine how much heat was required to heat 1 kg of this substance in the liquid state by 1 °C?
1) 750 J
2) 1200 J
3) 2000 J
4) 150000 J
6. When a piece of metal weighing 200 g is heated from 20 °C to 60 °C, its internal energy increases by 2400 J. The specific heat capacity of the metal is
1) 600 J/(kg O C)
2) 300 J/(kg O C)
3) 200 J/(kg O C)
4) 120 J/(kg O C)
7. The figure shows a graph of temperature versus time for the process of heating a lead ingot weighing 1 kg. How much heat did lead receive in 10 minutes of heating? 
Note.
The specific heat capacity of lead is considered equal to 130 J/(kg* O C)
1) 26 kJ
2) 29.51 kJ
3) 39 kJ
4) 42.51 kJ
8. The figure shows a graph of temperature t solid from the amount of heat Q received by him. Body weight is 2 kg. What is the specific heat capacity of the substance of this body? 
Write your answer in J/(kg O C)
By how many degrees did the temperature of 4 liters of water increase if it received an amount of heat equal to 168 kJ?
A silver ingot weighing 120 g transferred 1.5 kJ of heat to the environment when cooling from 66 to 16 °C. What is the specific heat capacity of the substance?
What is the mass of the iron part if 20.7 kJ of heat is spent on heating it from 20 to 20 O C?
HELP WITH PHYSICS, PLEASE)) AT LEAST SOME PROBLEMS)) REALLY NECESSARY 1) Determine the weight of a body weighing 1 kg at the equator and pole2) Determine the weight of the boy on the moon if his mass is 40 kg. On the moon g = 1.6 n/kg
3) A body weighing 1 kg on the moon is subject to a gravity force of 1.6 N. Determine the weight of a person weighing 50 kg on the Moon
4) A horse pulls a sleigh with a load along an icy road total mass 1 t. The coefficient of friction of the runners on the ice is 0.005. How much traction does the horse develop?
THANK YOU
equal to 1) 1 J 2) 0.38 J 3) 380 J 4) 3.8 J 10. A copper soldering iron cools from 200 to 150 0C. The mass of the soldering iron is 250 g. The amount of heat transferred to the environment is 1) 4.75 kJ 2) 19 kJ 3) 1380 kJ 4) 54.2 kJ 11. The specific heat capacity of brass is 380 J/kg 0C. This means that to heat 1) 380 kg of brass at 1 0C requires 1 J of energy 2) 1 kg of brass at 380 0C requires 1 J of energy 3) 1 kg of brass at 1 0C requires 380 J of energy 4) 1 kg of brass at 380 0C 380 J of energy are required 12. When burning peat weighing 4 kg and firewood weighing 6 kg 1) peat and firewood will give the same amount of heat 2) 90 70 С В А 80 t, min t,0C D Fig. 1 firewood will give more heat 3) peat will give more heat A16. The melting point of iron is 1539 0C. To melt iron scrap weighing 5 tons, having a temperature of 19 0C, an amount of heat is required equal to 1) 4.85 106 kJ 3) 3.99 106 kJ 2) 1.97 106 kJ 4) 1.47 106 kJ A17 . When 20 g of ether condensed, 8000 J of energy were released. The specific heat of vaporization of ether is 1) 4 · 102 J/kg 2) 4 · 103 J/kg 3) 4 · 104 J/kg 4) 4 · 105 J/kg A18. To convert 200 g of water heated to 100 0C into steam, energy equal to 1) 190 kJ 2) 340 kJ 3) 460 kJ 4) 500 kJ is required A19. Engine internal combustion equipped with 1) a car 2) a diesel locomotive 3) a ship 4) an A20 trolleybus. The wet thermometer of the psychrometer shows 150C, and the dry thermometer shows 200C. Relative humidity 1) 66% 2) 51% 3) 56% 4) 59%
1. A body with a mass of 2 kg is thrown vertically upward from the surface of the earth with a speed of 10 m.s. at what height is the potential and kinetic energy of the bodymatch up?
2. A body with a mass of 1 kg inelastically impacts a body at rest with a mass of 4 kg. what is the fraction of kinetic energy lost?
HELP SOLVE PROBLEMS!! NEED TO BE PASSED TOMORROW 1) A body with a mass of 90 kg moves at a speed of 16 m.s towards itA body weighing 75 kg moves at a speed of 30 m.s and couples with it; find the speed after coupling.
2) A cart weighing 250 kg moves in a horizontal direction with a speed of 40 ms and a person jumps from it at a speed of 6 ms relative to the cart in the direction of its movement. The mass of the person is 60 kg. Find the speed of the cart and the direction of its movement when the person jumped off it.
) A train with a mass of 2000 tons, moving in a straight line, increased its speed from 36 km/h to 54 km/h to find the change in momentum.
1. For everyone physical concept from the first column select the corresponding example from the second
column.
PHYSICAL CONCEPTS
EXAMPLES
A) physical quantity
B) physical phenomenon
B) physical law
(pattern)
1) inertial system countdown
2) the Earth communicates to all bodies near its surface
same acceleration
3) the ball released from the hands falls to the ground
4) stopwatch
5) average speed
2. Establish a correspondence between physical quantities and the formulas by which these quantities
are determined. Write down the selected numbers in the table under the corresponding letters. The numbers in the answer may be repeated.
PHYSICAL QUANTITIES
FORMULAS
A) specific heat capacity of the substance
1)
𝑚
2)qm
3) cm(t2-t1)
B) the amount of heat required for heating
solid
4) λm
𝑄
5)
𝑚(𝑡2 − 𝑡1)
B) specific heat of vaporization
3. Establish a correspondence between physical quantities and the formulas by which these quantities
are determined. 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. The numbers in the answer may be repeated.
PHYSICAL QUANTITIES
FORMULAS
1)
A) specific heat of fusion
𝑄
𝑚(𝑡2 − 𝑡1)
B) specific heat capacity of a substance
B) specific heat of combustion of fuel
5)
4. Establish a correspondence between physical quantities and their units of measurement in the SI system.
Write down the selected numbers in the table under the corresponding letters.
PHYSICAL QUANTITIES
A) amount of heat
B) specific heat capacity
B) specific heat of fusion
UNITS
1)
2)
3)
4)
5)
J/(kg °C)
J/°C
J/kg
J kg
J
5. What amount of heat will be released during the condensation of 2 kg of steam taken at the boiling point, and
subsequent cooling of water to 40 °C at normal atmospheric pressure?
1) 504 kJ
6. 1 liter of water at a temperature of 100 °C was added to water taken at a temperature of 20 °C. Mixture temperature
turned out to be equal to 40 °C. What is the mass? cold water? Heat exchange with environment neglect.
1) 1 kg
2) 2 kg
3) 3 kg
4) 5 kg
7. How much alcohol must be burned to heat 2 kg of water by 29 °C? Assume that all the energy released during the combustion of alcohol goes to heating the water.
1) 4.2 g
8. What amount of heat is needed to melt a piece of lead weighing 2 kg, taken at a temperature of 27 °C?
1) 50 kJ
9. Based on the results of heating a crystalline substance weighing 5 kg, a graph was drawn up of the dependence of the temperature of this substance on the amount of heat supplied.
Assuming that energy losses can be neglected, determine how much heat was required to heat 1 kg of this substance in the liquid state by 1 °C?
1) 750 J
10. When heating and subsequent melting of a crystalline substance weighing 100 g, it was measured
temperature and amount of heat imparted to a substance. Measurement data are presented in the form
tables. The last measurement corresponds to the end of the melting process. Considering it a loss
energy can be neglected, determine specific heat melting of a substance.
1) 480 J/ (kg C°)
2) 600 J/ (kg C°)
3) 120 J/ (kg C°)
4) 72 J/ (kg C°)
11. The figure shows a graph of the dependence of temperature t on time τ, obtained when the substance is uniformly heated by a heater constant power. Initially the substance was in
solid state.
Using the graph data, select two from the list provided. true statements. Specify
their numbers.
1) Point 2 on the graph corresponds to liquid state substances.
2) Internal energy of a substance during the transition from state 3 to state 4 increases.
3) The specific heat capacity of a substance in the solid state is equal to the specific heat capacity of this substance in the liquid state.
4) Evaporation of a substance occurs only in states corresponding to the horizontal section
graphic arts.
5) Temperature t2 is equal to the melting point of a given substance.
12. The student conducted a series of experiments to study heat transfer processes. For this he used
a calorimeter with a very small specific heat capacity, into which he poured varying amounts
water at a temperature of +20 °C. The student lowered bodies of equal masses, made of various materials and preheated to a temperature of +80 °C, he waited for thermal equilibrium to be established and, using a thermometer, measured (with an accuracy of 1 °C) how many degrees the temperature of the water in the calorimeter had increased. The measurement results are presented in the table:
№
experience
Specific
heat capacity
body, J/(kg ºC)
Weight
water, g
Promotion
temperature
water Δt, ºC
Which statements correspond to the results of the experimental measurements? From
from the proposed list of statements, select two correct ones. Indicate their numbers.
1) If, without changing other quantities, you change the mass of water by 2 times, then the increase in water temperature
will also change by 2 times.
2) With an increase in the specific heat capacity of the body, the increase in water temperature necessarily increases
3) If, without changing other quantities, the specific heat capacity of the body is increased, then the increase in water temperature will increase.
4) The specific heat capacity of water is much less than the specific heat capacity of the bodies used.
5) If, without changing other quantities, we increase the mass of water, then the increase in water temperature will decrease.
13. Using a glass of hot water, a thermometer and a clock, the teacher conducted experiments in class to study the temperature of cooling water over time. He entered the measurement results into a table.
t, °С
From the list provided, select two statements that correspond to the experiments performed. Indicate their numbers.
1) The water cools down to room temperature.
2) In the first 5 minutes. the water has cooled to a greater extent than in the next 5 minutes.
3) The temperature of the cooling water is inversely proportional to the observation time.
4) The cooling rate of water decreases as the water cools.
5) As it cools, the rate of evaporation decreases.