Systems, internal energy and specific heat
Answers are for parents and teachers.
1
Name one open, one closed and one nearly isolated system in your home.
Answers differ: for example an open cup, a closed bottle and a thermos flask.
2
Explain the difference between heat and temperature in two sentences.
Temperature measures the average kinetic energy of particles; heat is energy that moves because of a temperature difference.
3
A small and a big pot of water are at 60 °C. Which has more internal energy? Why?
The big pot: it has more particles at the same average kinetic energy.
4
Why is water used to cool car engines?
It has a high specific heat, so it takes up a lot of heat for a small rise in temperature.
5
Find the mistake: “A hot cup stores heat, so it has more heat than a cold bucket.”
Objects hold internal energy, not heat; a big cold bucket can have more internal energy than a small hot cup.