Question

a stone projected vertically upward with velocity U reaches a maximum height H.when it is at a height of 4h/5 from the ground the ratio of PE and KE at the point is ?​

Answer 1

Answer:

You can solve it using kinematics also.

But this method below is simple and involves less calculation.

As only conservative force(Gravity) acts on the stone,

So total mechanical energy is conserved.

At, height 4/5H

Let K.E. be x

Therefore, 4/5MgH + x = MgH(Conserving Mechanical energy between maximum height and at 4/5H).

x= 1/5MgH

Therefore, Ratio = x/4/5MgH = 1/4