Specific Heat Capacity
Year 9 🌡️ Energy & Thermodynamics Use Q = mcΔT to calculate heat energy transferred.
🌡️ What is Specific Heat Capacity?
Specific heat capacity (c) is the energy needed to raise the temperature of 1 kg of a substance by 1°C. Different materials need different amounts of energy.
| 🧪 Material | 📊 SHC (J/kg°C) | 📝 What this means |
|---|---|---|
| Water | 4200 | Needs a lot of energy to heat up (good coolant!) |
| Aluminium | 900 | Heats up quickly — good for cookware |
| Iron/Steel | 450 | Heats up twice as fast as aluminium |
| Copper | 390 | Good heat conductor and low SHC |
| Glass | 840 | Why glasses keep drinks warm |
📐 Using Q = mcΔT
This formula lets you calculate the energy transferred when heating or cooling a substance.
🌡️ Specific Heat Capacity
$$Q = mc\Delta T$$
$Q$ = heat energy (J) · $m$ = mass (kg) · $c$ = SHC (J/kg°C) · $\Delta T$ = temperature change (°C)
☕ Example: How much energy heats 0.5 kg of water by 80°C?
Q = 0.5 × 4200 × 80 = 168,000 J = 168 kJ
Q = 0.5 × 4200 × 80 = 168,000 J = 168 kJ
🔩 Find ΔT: 9000 J heats 2 kg of iron (c = 450 J/kg°C).
ΔT = Q ÷ (mc) = 9000 ÷ (2 × 450) = 10°C
ΔT = Q ÷ (mc) = 9000 ÷ (2 × 450) = 10°C
💡 Real-World Applications
The concept of specific heat capacity explains many everyday phenomena!
🌊 Sea breezes: Water has a high SHC — it heats up and cools down slowly. Land heats up quickly. By day: warm air over land rises, cool sea air comes in = sea breeze!
🚗 Car cooling systems: Water circulates through the engine, absorbing heat (high SHC = can carry lots of energy). Then the radiator cools the water down.
The oceans store huge amounts of thermal energy due to water's high SHC — this is what makes coastal climates milder!
Ready to test yourself? Click the Quiz tab above to answer questions on this topic!
🌡️ Specific Heat Capacity Calculator