How much energy, in joules, is released when 17 kilograms of granite is cooled from 45 C to 21 C?

The final answer is - 322, 320 Joules. The solution for the problem is:

The equation that must be used in this problem is:

U = mCp (Tf-Ti)

where:

U = energy released or absorbed in Joules

m = mass in kg

Cp = specific heat of material in J/kg-C

Tf = final temperature, C

Ti = initial temperature, C

Looking up the Cp of granite gives a value of 790 J/kg-C.

U = 17kg (790 J/kg-C) (21-45)

U = - 322, 320 Joules (negative means heat is released)