Which of these statements is not necessarily true for two objects in thermal equilibrium?
- The objects' temperatures are not changing.
- The objects are made of tiny particles that are moving at the same rate.
- The objects' temperatures have both changed by the same amount.
- The objects have the same temperature.
ans is: The objects are made of tiny particles that are moving at the same rate. At equilibrium, the tiny particles have the same kinetic energy but their movement rate depends also on their masses which may be different.