assign62k6

# assign62k6 - ◦ C to convert it to ice at − 5.0 ◦ C(b...

This preview shows page 1. Sign up to view the full content.

Physics 153 Assignment 6 Due Friday October 27, 2006 by 5:30pm 1. An aircraft engine takes in 9000J of heat and discards 6400J each cycle. (a) What is the mechanical work output of the engine during one cycle? (b) What is the thermal efficiency of the engine? 2. A certain nuclear-power plant has a mechanical-power output (used to drive an electric generator) of 330MW. Its rate of heat input from the nuclear reactor is 1300MW. (a) What is the thermal efficiency of the system? (b) At what rate is heat discarded by this system? 3. A freezer has a coefficient of performance of 2.40. The freezer is to convert 1.80kg of water at 25.0 C to 1.80kg of ice at 5.0 C in one hour. (a) What amount of heat must be removed from the water at 25.0
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ◦ C to convert it to ice at − 5.0 ◦ C? (b) How much electrical energy is consumed by the freezer during this hour? (c) How much heat is rejected to the room in which the freezer sits? 4. An inventor claims to have developed an engine that in each cycle takes 2.60 × 10 8 J of heat at a temperature of 400K, does 42.0kWh of mechanical work, and rejects heat at a temperature of 250K. Would you advise investing money to put this engine on the market? Why or why not? 5. A block of copper with a mass of 3.50kg, initially at 100.0 ◦ C, is dropped into 0.800kg of water initially at 0.0 ◦ C. (a) What is the final temperature of the system? (b) What is the total change in the entropy?...
View Full Document

## This note was uploaded on 07/20/2009 for the course PHYS physics 10 taught by Professor Goatman during the Spring '08 term at UBC.

Ask a homework question - tutors are online