Question

a man throws A ball of 500 gram in vertically upwards direction with a speed of 10 metre per second calculate the amount of work done by force of gravity in one second

Answer 1

Mass of the ball = 500 gram = 0.5 Kg (S.I.)
so force due to gravity = m×g = 0.5g or 5 N
now, using work = force × displacement
but as we do not know the displacement yet so we have to calculate displacement using 3rd equation of Newton baba ,

s = ut + 0.5 a (t)^2
s = (10)(1) + 0.5 (-10)(1^2)
s = 10 - 5
s = 5 m

so work done by gravity: 5×5 = 25 J