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.
. Calculate the work done by the piston when the air in the sleeve is compressed by a 
performing compressor with a force of 
.
is 
. Calculate by how much the spring is stretched if it was in an equilibrium position before stretching.
on the frozen snowy ground with a force of 
in the horizontal direction. The movement is inhibited by friction with a force of 
.
, 
, 
, 
, act on a body as shown in the figure below. Calculate the work done by all the forces over a distance 
.
parallel to the ground. Calculate the force with which the box is pushed if a work of 
is done while pushing the box.
, 
,
, 
. Calculate the total work done on the body by all the forces if they act over the distance 
.
is done when a force 
acts constantly on a body with mass 
lifting it through a distance of 
.
and a base radius of 
. It rotates about its axis through the center of gravity with frequency 
.
vertically upwards with a rope. How much work does he do to lift the load through a height of 
if he lifts it at:
?
if a force 
of 
stretches the same flexible coil spring by 
?
is pulled up an inclined plane at an angle 
to the horizontal with a force that is always parallel to the plane. If the coefficient of friction between the body and the plane is 
, how much work is done by the applied force to pull the body over a distance of 
at:
.
.
is pulled with force inclined at an angle 
with respect to a horizontal rough surface. The coefficient of friction 
between the body and the rough surface is 
. How much work is done when the force pulls the body over a distance of 
at:
,
?
is pulled on a horizontal rough surface. The coefficient of friction between the surface and the body is 
. How much work does the pulling force do to pull the body over the surface through a distance of 
if the body moves:
,
?
skates on a frozen lake. Calculate the work of the frictional force on the child after travelling a distance of 
if the coefficient of friction is 
.
and a radius of 
?
drives on a flat road at a speed of 
. The driver starts to brake suddenly with a braking force of 
. By how much is his speed reduced after 
of driving?
is fired into an 
thick wooden board. The speed of the bullet at the entrance to the plate is 
and at the exit 
. With what average force does the plate resist the bullet.
hits a wall and bounces off it at a speed of 
. By what percentage is the energy at reflection less than the incident energy. Where does the lost energy go?
and a radius of 
?
at a frequency of 
. How much work is done?
relative to the ice if his mass is 
, and the mass of the sledge is 
.
collides with a stationary body with mass 
. The collision is elastic. After the collision, the body with mass 
has kinetic energy 
.
after the collision and the initial velocity before the collision?
slides first on a smooth surface and then encounters a belt of rough surface (see figure).
runs at a constant speed 
. What is the driving force of the locomotive if the speed doubles on a route of 
?
and at speed 
lands in a stationary log with mass 
on a horizontal smooth surface. The projectile collision with the log is central. The projectile stops in the log after 
as shown in the figure below.
along a section of road through a settlement. What is the ratio between his kinetic energy 
and the kinetic energy 
if it were to travel through the settlement at the maximum permitted speed of 
?
, under the influence of a braking force of 
, steadily decelerates and stops after a certain time. The speed of the wagon just before the braking starts is 
.
, with a force of 
. The train has a mass of 
.The train speed along this distance increases from 
to 
.What is the frictional force?
and a radius of 
rotates at an angular velocity of 
. It is been placed on the ground so that it does not slip when in contact with the ground. How fast is it moving on the ground?
is thrown from a height of 
above the ground, in a horizontal direction at a speed of 
.
?
from 
to 
which travels for 
if the movement is inhibited by the force of friction? The coefficient of friction is 
.
in the direction of motion changes with the distance travelled as shown in Figure 1 below.
?
?
moving with a velocity 
collides with a stationary body of the same mass. If the collision is inelastic, how much of the kinetic energy is converted into internal energy?
heat. At the same time, it is compressed by a piston with an average force 
, the piston moving a distance of 
. By how much does the internal energy of the gas change? Does the gas energy increase or decrease?
if the speed of the center of gravity of the cylinder is 
?
, moving at a speed of 
from a height of 
covers a distance of 
.
moving at a speed of 
in a horizontal direction hits a fixed wooden board whose thickness d is 
. The missile exits on the other side of the board at a speed of 
. Assuming the board does not move during the collision.
. Using the energy balance, what is the maximum height reached by the ball?
which is initially at rest on a horizontal smooth surface, is acted upon by a force F which increases steadily from zero to 
in the first 
. The force is then maintained for the next 
.
from the beginning?
resting on a horizontal rough surface is pushed so that it begins to move in a horizontal direction at a speed of 
. The coefficient of friction between the body and the surface is 
.
is at rest on a horizontal rough surface. A constant force of 
, parallel to the surface begins to act on the body. If the coefficient of friction between the body and the surface is 
,
?
and 
as shown in the figure below. Initially, the bodies are held so that their centers of gravity are 
apart. Ignore friction, if the bodies are released:
across an iced surface and strikes a fence after covering a distance of 
. It bounces off the fence elastically and then slides on the ice for 
before stopping. What is the coefficient of friction between the pad and the iced surface?
travelling at a speed of 
applies the brakes and reduces its speed to 
after covering a distance of 
.
.
.
.
.
.
and decreases its potential energy by 
. The second body increases its kinetic energy by 
. What happens to its potential energy?
with a velocity 
. Using the energy balance, calculate the speed of the stone at height 
?
lands on the ground at a speed of 
. All its kinetic energy is converted into internal energy such that 
into the internal energy of plasticine and the rest into the internal energy of the wall. By how much does the internal energy of the lump increase and by how much does that of the wall increase also?
from its environment and emits 
work. What is the total energy change on the body in 
?
. How many kilograms of coal does it burn in one hour? The specific combustion heat of coal is 
.
. The car consumes 8 litres of gasoline per hour. What is the efficiency of the engine? The specific combustion heat of gasoline is 
and the density of gasoline is 
.
of electric power. It gives 
of heat to the space it heats every hour. What is the coefficient of performance of the heat pump? What is the heat flow rate from the surroundings?
and an efficiency of 
. What is the mass flow rate of the coolant that keeps the engine running at a constant temperature of 90 °C? The specific heat capacity of the coolant is 
, and its temperature before heat absorption is 20 °C. Assume that all excess heat is received by the coolant.
and density 
is used as the propellant.
if it starts driving with a full 5000-liter tank?
.
of power, and the useful transmitted power is 
. What is the efficiency of this engine? Is it an ideal heat engine? If not, what fraction of ideal efficiency is the efficiency of this steam engine?
, the specific heat capacity of water is 
, and the density of water is 
.
. How many litres of heating oil do we use if we heat 1 hectolitre of water from 25 °C to 100 °C? The density of the heating oil is 
and the specific heat capacity of water is 
.
and a cold tank temperature 
. The temperature of the hot tank of the first machine is increased by 
and the temperature of the cold tank of the second machine is decreased by 
the initial temperature of the hot tank is 200 °C.
)
per second. With what power does the falling water hit the bottom of the falls? 
.
.
, and the coefficient of friction on the slope is 0.3.
.
to 
.
and 
.
.
by supplying heat. The observed substances are iron, water, and air at room temperature. The mass of each substance is equal to 
.
of water is heated from 
to 
.
of water is cooled from room temperature by 
.
of water is heated from 
to 
.
.
of water at 
and 
of water at 
in a thermally insulated container and observe the final temperature at equilibrium to be 
. By how much has the internal energy of the warmer water, colder water, and total internal energy changed?
.
is ground with a grinding machine. After grinding, we measure that the piece has heated up by 
.
?
.
of heat.
of heat doing a work of 
.
. We add ice to the water, which cools the water by 
.
.
from 
to 
, we need to increase its internal energy by 
. Calculate the specific heat capacity of the iron rod.
is heated up by 
. By how much has its internal energy changed? The specific heat capacity of iron is 
.
grinding machine, the internal energy of a 
iron bar is increased by 
. How long have we been grinding?
of heat is passed to the air. The air in the tube expands and pushes the piston with a force of 
and moves it through a distance 
. By how much has the air's internal energy changed?
is full of water. By how much does the internal energy of the water in the pool change when it is cooled from 
to 
.
and the specific heat capacity of water is 
.
of a substance. If we increase the internal energy of this substance by 
, its temperature increases by 
.
?
. If the air resistance force against the car's motion is 600 N,
is located at an altitude of 400 m above a power plant. The water is channeled from the lake to a turbine and power plant generator. When the lake is completely emptied, the power plant releases 900 GJ of electrical energy.
