Question

A ball of mass 0.2kg is thrown vertically upwards by applying a force by hand. If the hand moves 0.2m while applying the force and the ball goes up to 2m height further, find the magnitude of force. (Consider g = 10m/s²).

Answer 1

We will solve it by energy conservation….

Work done by hand will change into potential energy=mgh

So work = f*s=mgh

Here s would be 0.2 meter for force by hand.. (force is applied while ball is in contact with hand)

And gravity will still work while ball is in contact with hand so h would be 2+0.2 meter

Thus f*0.2 =0.2*10*2.2( i have taken g =10m/s²)

F =22 N