Question

A piece of iron of mass 2.0 kg has a thermal capacity of 966 J/°C. Find: (i) Heat energy needed to warm it by 15°C, and (ii) Its specific heat capacity in SI unit.

A piece of iron with a mass of 2 kg has a thermal capacity of 966 J°C⁻¹

1. How much heat is needed to warm it by 15°C?
2. What is its specific heat capacity in S.I units?

Answer 1

Given: Thermal capacity = 966 J/°C

Mass = 2.0 kg

Temperature rise = 15°C

(i) Using Q = CΔT, where C is the thermal capacity:

= 966 × 15

= 14490 J

(ii) Q = m × C × T

Using c = `C/m`, and nothing that a temperature rise of 1°C equals 1 K:

c = `966/2.0`

= 483 Jkg⁻¹ K⁻¹