Goal: Hone the concept of heat and distinguish from internal energy.
Source: UMPERG-ctqpe191
Which of the following phrases best describes heat?
- The total energy possessed by a body.
- The flow of temperature to or from a body.
- The amount of energy dissipated by friction.
- The total energy flowing between two bodies at different temperatures.
- The useful work that could be extracted from a body.
Commentary:
Answer
(4) Many students are confused about what heat is because the term is
not used consistently. ‘Heat’ is usually used to refer to the thermal
energy that flows into or out of a body. So ‘heat’ is not equivalent to
‘energy’ and it is inappropriate to refer to the heat possessed by a
body. Unfortunately, the redundant phrase ‘heat flow’ is often used in
texts. In addition, students frequently attribute any loss of coherent
energy to friction, which has converted the energy into ‘heat’.