If an engine must do 500 joules of work to pull a 100 N load up to a height of 4 meters, What is the efficiency of the engine?

Answer 1

eff=workout/workin = 4*100/500 * 100=80percent

Answer 2

The force of gravtitation between two objects is 500 Newtons. What would the force of gravitation be if the distance between these to objects increased by 10 times?

Answer 3

10kg*9.81m/s^2=98.1N*4m=392.4J
392.4J/500=78.48% efficiency