Question

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

A. 327,992.8 J

  B. 365,575.3 J

  C. 901,980.3 J

  D. 785,662.8 J

Answer 1

327,992.8 J is the answer

Answer 2

Initially you need to find the specific heat of the granite. It is found in tables.

With that data, you can apply the equation: Q = m * C * ΔT


Where:

m = 17 kg

ΔT = 45°C - 21°C = 24 °C

And, from a table the specific heat, C, of granite is 790 J/kg°C

Therefore, you get: 17 kg * 790 J/kg°C * (24°C) = 332,320

This answer is pretty close to the option A, and you can conclude that the difference is due a small difference in the specific heat used.

Answer: option A.