A metal piece of mass 20g at 100°C is dropped into the calorimeter. After stirring, the final temperature of the mixture is found to be 22°C. Find the mass of water used in the calorimeter.
[specific heat capacity of the metal piece = 0.3Jg-1 °C-1]
[ specific heat capacity of water = 4.2Jg-1°C-1]
