Is this formula given in the exam?

No. SPM Physics papers provide no formula sheet, so this must be recalled.

What is the difference between heat capacity and specific heat capacity?

Heat capacity applies to a whole object (unit J °C⁻¹), while specific heat capacity is per kilogram (J kg⁻¹ °C⁻¹). Specific heat capacity lets you compare materials fairly regardless of how much you have.

Why does θ use temperature change, not the actual temperature?

Q = mcθ describes energy for a change of state of warmth, so only the difference matters. A change of 30 °C equals a change of 30 K, so you may use either scale for θ here.

Why does an experiment often give a c value that is too high?

Some heat escapes to the surroundings, so more energy Q appears to be needed for the same θ. This inflates the calculated c. Good insulation and a lid reduce this error.

Specific heat capacity Formula, SPM Physics

Specific heat capacity

Q = mcθ

Not given in the exam, recall it.

What it is for

Specific heat capacity is used in Heat (SPM Physics Form 4). Keep the SI units in every line of working. Heat

Symbols and SI units

Symbol	Meaning	SI unit
`Q`	heat energy	J
`m`	mass	kg
`c`	specific heat capacity	J kg⁻¹ °C⁻¹
`θ`	temperature change	°C

Rearrangements

c = Q / (mθ)
m = Q / (cθ)
θ = Q / (mc)

Worked example

Find the heat needed to raise 2 kg of water (c = 4200 J kg⁻¹ °C⁻¹) by 30 °C. Q = mcθ = 2 × 4200 × 30 = 252000 J = 2.52 × 10⁵ J.

Common trap

Use the value of c given in the question, and keep temperature change (not absolute temperature) in °C.

Understanding specific heat capacity

The equation Q = mcθ links the heat energy absorbed or released to the temperature change of a substance. Q is heat energy in joules (J), m is mass in kilograms (kg), c is the specific heat capacity in J kg⁻¹ °C⁻¹, and θ is the temperature change in degrees Celsius (°C).

The specific heat capacity tells you how much energy 1 kg of a material needs to warm by 1 °C. A high value, like water's 4200 J kg⁻¹ °C⁻¹, means the substance resists temperature change. To find other quantities, rearrange to c = Q / (mθ), m = Q / (cθ), or θ = Q / (mc).

Note that θ is a change, not an absolute temperature.

A worked example, step by step

How much heat raises the temperature of m = 0.5 kg of aluminium by 20 °C? Its specific heat capacity is c = 900 J kg⁻¹ °C⁻¹.

Write the formula: Q = mcθ. Substitute with units: Q = 0.5 kg × 900 J kg⁻¹ °C⁻¹ × 20 °C.

Multiply step by step: 0.5 × 900 = 450, then 450 × 20 = 9000.

So Q = 9000 J = 9.0 × 10³ J. Check the units: kg × J kg⁻¹ °C⁻¹ × °C leaves J, which is correct. The aluminium needs 9.0 × 10³ J, quoted to two significant figures.

Common mistakes and how this is tested

The key trap is using the c value given in the question and treating θ as a change, not the final temperature. If a block goes from 20 °C to 50 °C, then θ = 30 °C, not 50 °C.

More errors: mixing grams with kilograms in m; forgetting that heat lost by a hot body equals heat gained by a cold one in mixing problems; and ignoring heat lost to the surroundings, which makes an experimental c larger than the true value.

The command word calculate asks for the substitution with units. Define may ask for the meaning of specific heat capacity, and explain may ask why coastal areas have a smaller temperature range.

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

Written by the spmphysics.com.my editorial team.· Updated 5 Sept 2026