**Question: **3

**A piece of iron of mass 2.0 kg has a heat capacity of 966 J K-1. Find****(i) Heat energy needed to warm it by 15 ^{o}C, and**

**(ii) Its specific heat capacity in S.I unit.**

**Solution:**

(i) We know that,

Heat energy needed to raise the temperature by 15^{0} C = heat capacity × change in temperature

Heat capacity = 966 J K-1

change in temperature = 15^{0} C = 15 K

Heat energy required = 966 J K-1 × 15 K

Heat energy required = 14490 J

(ii) We know that,

Specific heat capacity = heat capacity / mass of the substance

Heat capacity = 966 J K-1

Mass = 2 Kg

Specific heat capacity = [ 966 / 2 ] J kg-1 K-1

Specific heat capacity = 483 J kg-1 K-1