| English | Thermal equilibrium |
|---|---|
| Bahasa Melayu | Keseimbangan terma |
| 中文 | 热平衡 |
Definition
The state reached when two bodies in contact are at the same temperature, so there is no net transfer of heat between them.
In exam terms
Thermal equilibrium is the state reached when two bodies in thermal contact are at the same temperature, so there is no net transfer of heat between them. Heat may still be exchanged both ways, but the rates are equal, giving zero net flow.
Before equilibrium, heat flows from the hotter body to the cooler one until their temperatures become equal. For example, a hot drink left in a room slowly cools and the room warms very slightly until both are at the same temperature; at that point they are in thermal equilibrium and the net exchange of heat stops.
Do not confuse it with…
Do not confuse thermal equilibrium with equal amounts of heat. Thermal equilibrium means equal temperature, not equal heat energy.
Two bodies in equilibrium share the same temperature, but a larger body can still hold much more heat energy than a smaller one at the same temperature.
In Paper 2 this is asked as state what is meant by thermal equilibrium or explain what happens when two bodies at different temperatures are in contact. State that heat flows from hot to cold until temperatures are equal, and then the net transfer of heat is zero.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)