Question

Suppose it is a particularly hot summer day and you want to make some popsicles to help cool off. You fill a popsicle mold with 0.15kg of juice (suppose it is the same thermal energy as water). The juice starts out at a temperature of 30 °C and the freezer will cool it to -20 °C. a. How much heat must be removed from the popsicles in order to bring them to their final temperature. b. Draw an energy flow diagram to show the heat and work flows in this situation, and determine the minimum work needed by the freezer to remove this amount of heat from the inside of the freezer Assume the inside of the freezer remains a stable -20 °C and the outside remain 30 °C. c. If a gas fired power plat operated with 40% of efficiency, how much heat would have to be added, QH, to produced this much work? If the exhaust temperature is at 20 °C, what is the minimum TH needed to achieve this efficiency. I posted this question once and someone answered it. I solved it base on his response and showed it to my instructor who said part b and c is wrong. Can you please help me again. thank you

Answer 1