(2xPiexl)/(p)
(Piexl)/(2xp)
(2xPiexp)/(l)
(Piexp)/(2xl)
On compressing the spring
On stretching a spring
On moving a body against gravitational pull
On raising an air bubble in water
100 watts
75 watts
60 watts
50 watts
Rings in cylinders
Crankshaft bearings
Brake shoe linings
Wheel hole bearings
