Jack pushed and pushed, but no matter how hard he tried, the refrigerator would not budge! what is the best explanation of what happened? a) jack exerted a force and did work. b) jack had no energy and did no work. c) jack used all his potential energy to do work. d) the refrigerator did not move so no work was done.

Ahot-air balloon is drifting straight downward with a constant speed of 2.40 m/s. when the balloon is 7.63 m above the ground, the balloonist decides to drop one of the ballast sandbags to the ground below. how much time elapses before the sandbag hits the ground?

Agas contained within a piston-cylinder assembly undergoes three processes in series: process 12: compression with pv= constant from 1 bar and 1 liter to 4 bar. process 23: constant pressure expansion to 1 liter. process 31: constant volume calculate the pressure and volume at each state, and sketch the processes on a p-vdiagram labeled with pressure and volume values at each numbered stat

What is the most useful equation for electric power?