Question

Gravitational force acts on all bodies in proportion to their masses. Why, then, doesn't a heavy body fall faster than a lighter body?

Answer 1

1. As we know from the law of gravitation, the force of attraction on the body by the earth is given by

$F=G{M}_{e}m/r^2$

where,

$M_e$ is the mass of earth,

$m$is the mass of the body,

$r$ is the distance between centre of earth and the centre of body

$G$ is the universal gravitational constant.

2. Acceleration due to gravity (g) is given by

$g=F/m=GMe/r^2$ ( from Newton's second law of motion)

Thus, acceleration due to gravity is independent of the mass of the body.

Hence, both heavy and light bodies fall with the same acceleration ($g=9.8m{s}^{-2}$ , near the surface of the earth)