Question

36. A stone is released from a height of 10 m. Its potential energy at the highest point is 1000 J.
Find the following: (Take g = 10 m/s²)
i. Its potential energy at height 5 m from the ground
ii. Its kinetic energy at a height of 5 m from the ground
iii. The sum of kinetic and potential energies at a height of 5 m from the ground
iv. The kinetic energy just before impact
V. Compare the final answer values of (iii) and (iv) and state which law is
responsible for the observation.​

Answer 1

Answer:

Gravitational potential energy near the surface of the earth( where the acceleration due to gravity has the constant value) is directly proportional to the height from the surface. At a height h potential energy =mgh

Kinetic energy =0

At a height

5

4h

potential energy =

5

4

mgh.

The difference mgh - 4/5mgh= 1/5mgh is the kinetic energy.

The ratio of kinetic energy to potential energy is 1:4.