Assuming earth to be a sphere of uniform mass density, how much would a body weigh half way down the centre of the earth, if it weighed 100 N on the surface ?

Explanation

To determine how much a body would weigh halfway down to the center of the Earth, we can follow these steps:

### Step 1: Understand the Weight on the Surface
The weight of the body on the surface of the Earth is given as 100 N. This weight can be expressed using the formula:
\[ W = mg \]
where \( W \) is the weight, \( m \) is the mass of the body, and \( g \) is the acceleration due to gravity at the surface.

### Step 2: Calculate the Mass of the Body
...