Hoists

….The car gains 2.35 x 10^4 J of gravitational potential energy during the process. What is the efficiency of the hoist?

A. 7.00%
B. 17.5%
C. 25.0%
D. 34.9%

An Internal combustion engine has an efficiency of 20.0%. This engine is used to deliver 6.00 x 10^4 J of work to the rest of the drive train. What is the total energy input?
A. 1.20 x 10^3 J
B. 4.80 x 10^3 J
C. 7.20 x 10^4 J
D. 3.00 x 10^5 J

List the following engine types in order of increasing efficiency
Daimler engine
Newcomen steam engine
Savery engine
Otto engine
Watt steam engine

(2.35*10^4)/(6.73*10^4) *100 = 34.9% Answer D is correct

100/20*(6.00*10^4) = 300,000J = 3*10^5J

Last part of your question:
Sorry you will have to look these up. This is something that does not require any calculation, and is merely reading up references, which you can do yourself

One Response to “a hoist lifts a car with a total energy input of 6.73 x 10^4 J… - PLEASE, PLEASE help!!!?”