Chapter 7 Heat and Phase Transitions 9. You stir 1 kg of water until its temperature rises by 1. How much work did you do on the water?

Chapter 7 Heat and Phase Transitions
9. You stir 1 kg of water until its temperature rises by 1. How much work did you do on the water?
10. While polishing a 1-kg brass statue, you do 760 J of work against sliding friction. Assuming that all the resulting heat flows into the statue, how much does its temperature rise?
11. You drop a lead ball on a cement floor from a height of 10 m. When the ball stops bouncing. How much will its temperature have risen?
12. Roughly how high could a 300 K copper ball life itself if it could transform all its thermal energy into work?
13. Drilling a hole in a piece of wood takes 1000 J of work. How much does the total internal energy of the wood and drill increase as a result of this process?
14. An ideally efficient freezer cools food to 260 K. If room temperature is 300 K, how much work does this freezer consume when removing 100 J of heat from the food?
15. An ideally efficient refrigerator removes 900 J of heat from food at 270 K. How much heat it then deliver to the 300 K room air?
16. An ideally efficient heat pump delivers 1000 J of heat to room air at 300 K. If it extracted heat from 260 K outdoor air, how much of that delivered heat was originally work consumed in the transfer?
17. An ideally efficient air conditioner keeps the room air at 300 K when the outdoor air is at 310 K. How much work does it consume when delivering 1240 J of heat outside?
18. An ideally efficient airplane engine provides work as heat flows from 1500 K burned gases to 300 K air. What fraction of the heat leaving the burned gases is converted into work?
19. An ideally efficient steamboat engine operates on 500 K steam in 300 K weather. How much work can it obtain when 1000 J of heat leaves the steam?
20. An offshore breeze at the beach is powered by heat flowing from how land (310 K) to cool water (290 K). Assuming ideal efficiency, how much work can this breeze provide for each 1000 J of heat it carries away from the land?
21. An ideally efficient solar energy system produces work as heat flows from the 6100 K surface of the sun to the 300 K room air. What fraction of the solar heat can it transform into work?