A body of mass m kg starts falling from a distance 2R above the earth's surface. What is its kinetic energy when it has fallen to a distance 'R' above the earth's surface ? (where R is the radius of Earth)

Explanation

To solve the problem of finding the kinetic energy of a body of mass \( m \) kg that starts falling from a distance \( 2R \) above the Earth's surface and has fallen to a distance \( R \) above the Earth's surface, we can follow these steps:

### Step 1: Understand the Potential Energy at Different Heights
The gravitational potential energy (PE) of an object at a distance \( d \) from the center of the Earth is given by the formula:
\[ PE = -\frac{GMm}{d} \]
where \( G \) is the gravitational constant, \( M \) is the mass of the Earth, and \( m \) is the mass of the object.
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