Question

A body weights $500$N on the surface of the earth. How much would it weight half was below the surface of the earth?

• A. $1000$N
• B. $500$N
• C. $250$N
• D. $125$N

Answer 1

The correct option is C $250$N

Value of acceleration due to gravity decreases on going below the surface of the earth. weight(w) of a body is defined as product of mass(m) and acceleration due to gravity(g) $w=mg$.
The value of g below the surface of earth at a distance h is given by
$g^{\prime }=g\left(1-\frac{h}{R}\right)$
$\Rightarrow W^{\prime }=W\left(1-\frac{h}{R}\right)$
Given, $h=\frac{R}{2},W=500$N.
$W^{\prime }=500\left(1-\frac{1}{2}\right)$
$=\frac{500}{2}=250$N.