Practice Thermal Energy in Physics
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
The total kinetic energy of all particles (atoms and molecules) in an object due to their random motion.
The energy of jiggling atoms and molecules—what we experience as temperature.
Showing a random 20 of 50 problems.
Example 1
mediumMixing 1 kg of water at 80°C with 1 kg at 20°C (no losses), what is the final temperature?
Example 2
hardA car traveling at brakes to a stop. If all kinetic energy is converted to thermal energy in the brakes ( of steel, ), by how much do the brakes heat up?
Example 3
mediumHow much heat raises 0.25 kg of water from 20°C to 80°C? (water )
Example 4
challenge0.2 kg of metal at 150°C () is placed in 0.5 kg water at 20°C (). Find the equilibrium temperature (no losses).
Example 5
easyHeat 0.5 kg of aluminium () by 20°C. Find the heat required.
Example 6
easyTrue or false: heat and thermal energy are the same thing.
Example 7
easyTrue or false: thermal energy is the total kinetic energy of all particles in an object due to random motion.
Example 8
easyTwo identical copper blocks are at 50°C and 80°C. Which has more thermal energy?
Example 9
easy of iron () is heated by . Find the heat required.
Example 10
easyHow much heat is needed to raise 2 kg of water by 10°C? (water )
Example 11
mediumAn kettle heats of water () from to . Ignoring losses, find the time required.
Example 12
medium of ice at is added to of water at . Latent heat of fusion of ice ; water . Find the final temperature (assume all ice melts).
Example 13
hard of water at is poured into a glass cup () at (water ). Find the equilibrium temperature, ignoring losses.
Example 14
mediumEqual heat is given to water (), causing a rise, and to oil (). Find the oil's temperature rise.
Example 15
easy of copper () cools by . Find the heat released.
Example 16
easyA gas is heated and its particles move faster. What happened to its thermal energy?
Example 17
challengeWater at the base of a waterfall converts all gravitational PE into thermal energy of the same water. Find the temperature rise. (, )
Example 18
easyA substance loses 5000 J of thermal energy. Did its particles speed up or slow down on average?
Example 19
easyIf 3 kg of water cools by 5°C, how much thermal energy does it release? (water )
Example 20
challengeA 0.05 kg lead bullet () at 30°C hits a wall at 200 m/s and stops. If half its KE becomes thermal energy in the bullet, find its temperature rise.