What is the change in internal energy for a system which loses 422 J of heat, and on which 227 J of work is done?

It has been determined that the body can generate 5500 k) of energy during one hour of strenuous exercise. Perspiration is the body's mechanism for eliminating this heat. What mass of water would have to be evaporated through perspiration to rid the body of the heat generated during 4 hours of exercise? (The heat of vaporization of water is 40.6 kJ/mol.) Mass = kg

An automobile engine generates 2210 Joules of heat that must be carried away by the cooling system. The internal energy changes by -2823 Joules in this process. Calculate w for the engine. This represents the work available to push the pistons in this process. Work = J

During a certain chemical reaction 255 J of heat is absorbed by the system and 275 J of work is done on the surroundings. Calculate the change in internal energy of the system. Do not type units with your answer. Your Answer: