Calculate the amount of heat required to heat a 3.5-kg gold bar from 21 °C to 67 °C.
Specific heat Cp of gold is 0.129 J per dc per g.
Heat required to heat m g of a material of specific gravity Cp from temperature T1 degree Celsius to T2 degree Celsius is given by
H = m Cp (T2-T1)
Here m = 3.5 Kg = 3500 g
Cp = 0.129 J per dc per g.
T1 = 21 dc
T2 = 67 dc
So H = 3500 X 0.129 X ( 67-21) = 3500 X 0.129 X 46 = 20769 J or 20.769 KJ