Heat: Key Terms (Form 4 SPM Physics)

Terms and definitions

• Temperature, A measure of the degree of hotness of a body, related to the average kinetic energy of its particles; measured in degrees Celsius (°C) or kelvin (K).
• Heat, The energy transferred between bodies because of a difference in temperature; a form of energy measured in joules (J).
• Thermal equilibrium, The state reached when two bodies in contact are at the same temperature, so there is no net transfer of heat between them.
• Heat capacity, The amount of heat needed to raise the temperature of an object by 1 °C (or 1 K); measured in J °C⁻¹ or J K⁻¹.
• Specific heat capacity, The amount of heat needed to raise the temperature of 1 kg of a substance by 1 °C (or 1 K); measured in J kg⁻¹ °C⁻¹.
• Latent heat, The heat absorbed or released when a substance changes state without any change in temperature.
• Specific latent heat, The heat needed to change the state of 1 kg of a substance without a change in temperature; measured in J kg⁻¹.
• Boyle's law, For a fixed mass of gas at constant temperature, the pressure is inversely proportional to its volume (pressure × volume = constant).
• Charles's law, For a fixed mass of gas at constant pressure, the volume is directly proportional to its absolute temperature.
• Pressure law, For a fixed mass of gas at constant volume, the pressure is directly proportional to its absolute temperature.
• Absolute zero, The lowest possible temperature, 0 K or about −273.15 °C, at which the particles of a substance have minimum kinetic energy.
• Absolute temperature scale, The temperature scale that begins at absolute zero and is measured in kelvin (K), where a change of 1 K equals a change of 1 °C.
• Base quantity, A physical quantity that cannot be defined in terms of other physical quantities; the five in physics are length, mass, time, electric current and temperature. (related term from another chapter)
• Derived quantity, A physical quantity obtained by combining base quantities through multiplication or division, such as speed or density. (related term from another chapter)
• Scalar quantity, A physical quantity that has magnitude only, with no direction, such as distance, speed and mass. (related term from another chapter)

Content standards these terms come from

• 4.1 Thermal Equilibrium
• 4.2 Specific Heat Capacity
• 4.3 Specific Latent Heat
• 4.4 Gas Laws

How to learn them

1. Cover the definition, say it aloud, then check the unit.
2. Pair each term with a formula or experiment from the chapter.
3. Write the Malay term alongside the English one, SPM papers are bilingual.

More Heat resources

• Chapter overview: Heat
• Revision Notes
• Common Mistakes
• Practice Questions
• Paper 2 Answering Guide
• Paper 3 Guide
• Calculation practice sets

Source: DSKP KSSM Physics Form 4 and 5 (Versi English), Sijil Pelajaran Malaysia: Format Pentaksiran mulai 2021, Fizik (4531) (Bahagian Pembangunan Kurikulum (BPK), KPM)