1. A thermos bottle contains 3.6 kg of water and 1.8 kg of ice in thermal equilibrium at 0oC. How much heat is required to bring the system to thermal equilibrium at 48oC? Specific heat of water is 4,186 J/kg·°C; latent heat of fusion of water is 3.35 x 105 J/kg.
2. What is the minimum amount of energy required to completely melt a 4.52 kg lead brick which has a starting temperature of 21.4oC? The melting point of lead is 328oC. The specific heat capacity of lead is 128 J/kg·°C; and its latent heat of fusion is 23,200 J/kg.