# Heat and the First Law of Thermodynamics

Consider Joule's apparatus described in Figure 20.1. Each of the two masses is 1.50 kg, and the tank is filled with 190 g of water. What is the increase in the temperature of the water after the masses fall through a distance of 3.50 m?

For this I know that PE=W, and that 2mgh is proportional to the change in temperature, but for some reason I can't get the correct answer

2(1.5 g)(9.8 m/s2)(3.5m)=103 C, but this is not correct

$$W = c m \Delta T$$