Solar houses are designed to retain the heat absorbed during the day so that the stored heat can be released during the night. A botanist produces steam at 100 C during the day, and then allows the steam to cool to 0 C and freeze during the night. How many kilograms of water are needed to store 200 kJ of energy for this process? (Use the latent heat of vaporization of water Ly= 22.6 105 J/kg, the latent heat of fusion of water L= 33.5 10 J/kg, and the specific heat capacity of water c=4,186 J/kg-K)