You want to take a hot bath in your mountain cabin. Your bathtub holds 200L of water. The stream outside is your only source of water and it is cold (6 °C). You need to heat
your bathwater to 40 °C. Your only source of fuel is beetle-killed wood (which has a heat
content of 18kJ/g.
a) How much heat energy is required to heat the water in your bathtub?
b)How many kg of wood would you need to burn 100% efficiency to heat your tub?
c)Assuming you are only 30% efficient in heating your water with the wood fire, how many kg of wood would you need to burn to heat your bathtub?