The weather drops to 5 degrees celcius (T1) so to keep warm, you offer to make hot soup for the entire group. The cannister for the gas burner has 20grams of fuel left. The heat of combustion of the fuel (Hr) in the cannister is 46.2 MJ/kh, 50% of the combustible heat is usable for heating a pot of water and the water temperature needed to make the soup is 60 degrees celcius (T2). The average heat capacity of water is 4.2 kJ/(kg.K).
Calculate the mass of water in kg that can be heated for the soup. Is it worth heating the water to make the soup. How much thermal energy will each hiker receive if they drink all the soup. Explain your answer.