Problem 78P

Calculate the amount of heat required to heat a 3.5-kg gold bar from 21 °C to 67 °C.

Solution 78P

Answer :

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