4. which of the following is true regarding nuclear fission and nuclear fusion? a. both of these processes are equally complex to control. b. nuclear fission involves combining elements, while nuclear fusion involves breaking down elements. c. our sun's heat is an example of both of these processes. d. both of these processes can provide energy.

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.