Heat and temperature ________________________________________________________________ 14. Heat and thermal equilibrium
Figure 7.9Faster-moving particles of the warmer substance bump into and transfer some of their energy to slower-moving particles of the cooler substance.
Thermal energy is transferred in this way until both substances have the same temperature.
The transfer of energy stops when both bodies or systems reach the same temperature.
Q&A
Q: How is thermal energy transferred in an oven?
A: Thermal energy of the hot oven is transferred to the cooler food, raising its temperature.
Cooling Down by Heating Up
How do you cool down a glass of room-temperature cola?
You probably add ice cubes to it, as in the figure below. You might think that the ice cools down the cola, but in fact, it works the other way around. The warm cola heats up the ice.
Thermal energy from the warm cola is transferred to the much colder ice, causing it to melt.
The cola loses thermal energy in the process, so its temperature falls.