| English | Heat |
|---|---|
| Bahasa Melayu | Haba |
| 中文 | 热 |
Definition
The energy transferred between bodies because of a difference in temperature; a form of energy measured in joules (J).
In exam terms
Heat is the energy transferred between bodies because of a difference in temperature. It is a form of energy, so it is measured in joules (J), and it always flows from the region of higher temperature to the region of lower temperature.
When heat is added to a body it can raise the temperature (Q = mcθ) or change the state of the body (Q = ml) without changing temperature. For example, supplying 4200 J to 1 kg of water with specific heat capacity 4200 J kg⁻¹ °C⁻¹ raises its temperature by θ = Q/(mc) = 4200 J ÷ (1 kg × 4200 J kg⁻¹ °C⁻¹) = 1 °C.
Do not confuse it with…
Do not confuse heat with temperature. Heat is the amount of thermal energy transferred, measured in joules; temperature measures the degree of hotness and is related to the average kinetic energy of particles, measured in °C or K. Two objects can be at the same temperature yet contain very different amounts of heat.
In Paper 2 this is asked as define heat or explain why heat flows from a hot to a cold body. State that heat is energy transferred because of a temperature difference, and that flow continues until both bodies reach the same temperature (thermal equilibrium).
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)