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to 
if the area of the apartment is 
and the height is 2.6 m.
, density of air = 
).
is poured into a bottle and a thermos. After one hour, the temperatures in both vessels are measured again and the water in the thermos measures 
while that of the bottle measures 
.
.
and then cooled slowly. The graph below shows how its temperature changes over time. What is the rate of flow of heat from the sphere after the first 40 minutes of cooling?
.
transfers heat 
during 
. In what time in terms of time 
transfer heat, 
?
is heated on a hob. The water temperature changes over time as shown in the graph below. What is the heat flow rate from 0 to 10 minutes? What is it like in 10 to 15 minutes? The power of the heater is not changed during the experiment.
.
and that of aluminium is 
.
, heat quantity 
is transferred to a body in time 
. After what time, in terms of 
for two values of heat flow rate is given. The red line in the graph represents the heat flow rate 
and the blue, 
. Calculate the values of the heat flow rate on both lines. Which is bigger?
? Draw the graph.
.
.
to 
?
, 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 
.
, while the second and fourth have a thickness of 2 cm and a thermal conductivity of 
. The first layer encloses the interior of the refrigerator with a temperature of 
, and the fourth layer is outside, where the temperature is 
. What is the temperature 
in the middle of the third layer?
has an area of 
and a thickness of 0.4 m. A 
surface window is built into the wall. The window allows a heat flow rate of 1.6 W per square meter of the surface at a temperature difference of 1 K. The difference between the indoor and outdoor temperature is 20 K. What is the heat flow rate through the wall with the window? How much heat is lost in one day?
. Calculate the heat flow per square metre of the Earth's surface. What would be the temperature on the Earth's surface if the surface were not cooled or heated further?
(solar constant). What is the temperature of the plate when thermal equilibrium is established? Calculate for the following two cases:
and is heated to a temperature of 
. The ambient temperature is 
. What is the heat flow rate from the stove if it radiates like a black body?
. A container with 1 l of water at a temperature of 
is placed in the freezer. Calculate how much heat the water gives off at the time it cools to the temperature in the freezer. The specific heat capacity of water is 
, the specific heat capacity of ice is 
and the specific heat of fusion of water is 
.
and surface area 
has a thickness of 
. The temperature outside the house is 
and the inside is 
.
appear?
has an area of 
. If the heat flow rate through the wall is 360 W and the temperature of the inside face of the wall is 
, what is the temperature of the outside face of the wall?
. If the wall has a recess of 0.2 m inside it, what should be the thickness of the insulator that will be inserted in the recess in order to prevent heat losses?
and 
respectively).
. It is followed by a 40 cm thick brick with a thermal conductivity of 0.8 
. The pot has a bottom with an area of 
and a thickness of 
. It receives heat from the stove only through the bottom.
and an outside temperature 
. What is the heat flow rate through the wall? Where in the wall are the negative temperatures?
.
. The temperature outside the cylinder is 
. If the water is heated with a 6 kW heater, what must be the thickness of the wall of the container in order to keep the water at a constant temperature at all times?
surface of the wall will be 3 W? The difference between the temperatures of the inner and outer sides of the coated wall is 
. The thermal conductivity of hollow bricks is 0.6 
and that of styrofoam is 0.04 
on the inside and 
on the outside. What is the ratio of the heat loss through the window to that through the wall?
and a 30 cm thick bricks with thermal conductivity 
.
and a temperature of 
. The emissivity of the skin is 0.3. Calculate the power of an electric heater that would replace the adult's radiation.
.
while the aluminum end is immersed in a mixture of water and ice at a temperature of 
. What is the temperature at the junction of the two bars?
. The light bulb is supplied with electricity by 2 W batteries. The air in the container has a temperature of 
before the light bulb is turned on. What will be the air temperature after 30 minutes?
.
is immersed in the liquid. The heater is switched on and, when the liquid is boiling, balance readings 
are taken at corresponding times 
. A graph of the variation with time 
of vaporisation
and leaves the tube at a temperature of 
. The mass of liquid flowing through the tube per unit time is 
. Electrical power 
is dissipated in the heating coil. The student changes 
. A mass of 
of water at 
is poured into the kettle. When the kettle is switched on, it takes 2.0 minutes for the water to start boiling. In a further 7.0minutes, one-half of the mass of water is boiled away. Estimate, for this water, the specific latent heat of vaporisation.
is increased from 
to 
at constant volume. The specific heat capacity of the gas for this change is 
. Calculate the energy supplied to the gas by heating.
at a temperature of 
. The gas is cooled to its boiling point of 
. Assume all the gas condenses to a liquid. For this change, the specific heat capacity of nitrogen gas is 
and the specific latent heat of vaporisation is 
. Determine the thermal energy, in 
, removed from the nitrogen gas.
of a substance. The variation with time of the temperature of the substance is shown in the figure below. The substance is perfectly insulated from its surroundings.
. Use data from the figure above to calculate, in 
, the specific latent heat of vaporisation 
of the substance.
silver by weight. The jeweller melts some pure gold and then adds the correct weight of silver. The initial temperature of the silver is 
. Use the data in the figure below to calculate the initial temperature of the pure gold so that the final mixture is at the melting point of pure gold.
of ice at 
is taken from a freezer and placed in a beaker containing 
of water at 
. Data for ice and for water are given in the figure below.
.
has a hollow in its top surface, as illustrated in the figure below.
of water at 
is poured into the hollow. The water has specific heat capacity 
. Some of the ice melts and the final mass of water in the hollow is 
. Assuming no heat gain from the atmosphere, calculate a value, in 
, for the specific latent heat of fusion of ice.
of water at 
. A cube of ice of mass 
is put into the water. Initially, the ice is at 
. The water, of specific heat capacity 
, is stirred until all the ice melts. Assuming that the cup has negligible mass and that there is no heat exchange with the atmosphere, calculate the final temperature of the water. The specific latent heat of fusion of ice is 
.
. When the water in the kettle is boiling at a steady rate, the mass of water evaporated in 2.0 minutes is 
. The specific latent heat of vaporisation of water is 
. Calculate the rate of loss of thermal energy to the surroundings of the kettle during the boiling process.
is 
. A mass of 
of liquid water at 
is provided with the thermal energy needed to vaporise all of the water at atmospheric pressure. Calculate the thermal energy 
supplied to the water.
. The liquid is supplied with thermal energy at a rate of 
. The beaker has a mass of 
and a specific heat capacity of 
. The beaker and the liquid are in thermal equilibrium with each other at all times and are insulated from the surroundings. The figure below shows the variation with time 
of the temperature of the liquid.
, of the liquid.
, as shown in the figure below.
. The heater is switched on and readings of the temperature of the block are taken at regular time intervals. When the block reaches a constant temperature, the heater is switched off and then further temperature readings are taken. After the heater has been switched off, the maximum rate of fall of temperature is 
per minute. Estimate the specific heat capacity of aluminium.
is placed in a funnel together with an electric heater, as shown in the figure below.
and specific heat capacity 
. The actual temperature of the oil is 
. The bulb of the thermometer has mass 
and an average specific heat capacity of 
. Before immersing the bulb in the oil, the thermometer reads 
. The thermometer bulb is placed in the oil and the steady reading on the thermometer is taken. Determine
.
. A mass of 
of water at 
is poured into the kettle. When the kettle is switched on, it takes 2.0 minutes for the water to start boiling. Estimate, for this water, the specific heat capacity.
contains a mass of 
of warm water at a temperature of 
, as illustrated in the figure below.
of ice at 
is taken from a freezer and put into the water. The ice melts and the final temperature of the can and its contents is 
. Data for the specific heat capacity 
of aluminium, ice, and water are given in the table below.
,
for the specific latent heat of fusion of ice.
of ice melted in 5.0 minutes is noted, together with the power 
of the heater. The power 
of ice,
of thermal energy gained by the ice from the surroundings.
