What is the power when a crane lifts a piece of pipe from the ground to a certain height, doing 15000 J of work in 25s?
A) 375000 W

B) 600 W

C) 100 W

D) 350 W

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e