Energy Conversion During Free Fall
When a body is held at a certain height, it possesses potential energy due to its position in a gravitational field. This stored energy is called gravitational potential energy.
As the body is allowed to fall freely under gravity:
- Its height above the ground decreases.
- Its speed (velocity) increases.
Potential energy is directly related to height, while kinetic energy is related to speed. As the potential energy decreases because the height is reducing, this energy is transformed into kinetic energy, which increases because the speed is increasing.
According to the principle of conservation of energy, energy cannot be created or destroyed, only converted from one form to another. In the case of a freely falling body (neglecting air resistance), the potential energy at the top is converted into kinetic energy as it falls.
Therefore, the potential energy is converted into Kinetic energy.
Important Questions from Gravitational potential energy
Statement I: A body weighs less on a hill top than on earth's surface even though its mass remains unchanged.
Statement II: The acceleration due to gravity of the earth decreases with height.- The work done to raise a mass $m$ from the surface of the Earth to a height $h$, which is equal to twice the radius of the Earth $R$, is:
Mass of the earth is M and its radius is R. An object of mass m is placed on the surface of earth. Find the work done in lifting the object through a height \(\frac{R}{2}\) above the surface of earth.
Mass of uniform circular ring is M and its radius is R. Find the maximum intensity of gravitation field on the axis of the ring
A solid sphere of constant density p has mass M and radius R. What is the gravitational potential difference between a point P which is at distance \(\frac{R}{2}\) from the central and its surface?
(i.e. Vp - Vsurface)
