A piece of metal weighing 20 kg was heated from 20 to 100 ° C, giving it an amount of heat equal to 800 kJ.

A piece of metal weighing 20 kg was heated from 20 to 100 ° C, giving it an amount of heat equal to 800 kJ. Find the specific heat of the substance from which the body is made.

The amount of heat required to heat the metal:
Q = С * m * (tк – tн), where Q is the amount of heat expended for heating (Q = 800 kJ = 800 * 10³ J), С is the specific heat capacity of the metal (J / (kg * K)), m is the mass metal (m = 20 kg), tк – the final temperature of the metal (tк = 100 ºС), tн – the initial temperature of the metal (tн = 20 ºС).
С = Q / (m * (tк – tн)) = 800 * 10³ / (20 * (100 – 20)) = 500 J / (kg * K).
Answer: The specific heat of 500 J / (kg * K) corresponds to steel.