A hole is drilled half way to the centre of the Earth. A body is dropped into the hole. How much will it weigh at the bottom of the hole if the weight fo the body on the Earth's surface is 350 N?

Explanation

Given : Weight of the body on Earth's surface, W = mg = 350 N.
Body is thrown at depth,
Depth, `d=(R )/(2)`
Where R is the radius of the earth.
At depth d, the acceleration due to gravity is given by,
`g_(d)=g[1-(d)/(R )]`
`therefore ` Weight of the body at depth d is
`W_(d)=mg_(d)=mg[1-(d)/(R)]`
`=350 [1-(R//2)/(R)]`
`=350 xx (1)/(2)`
` =175 N.`