A 40 gal water heater contains 160Kg of H20. How much energy is added to get water ffrm 10C to 60C?

Question

A 40 gallon water heater contains 160 Kg of water. The water coming from the water company is at 10 C (50 F; when it comes out of the water tank, its temperature is 60 C (140 F). How much energy does the water heater add?

Answer 1

The specific heat of water is 4180 J, meaning it takes 4180J to raise the temperature of 1 Kg of water 1 degree C.

Therefore, 4180 * 50 = 209000 J, or 209 Kj. Since the water is not changing states, there's no latent heat to worry about. :)