Question

Why does a heavier object hit the ground first when dropped from the same height?

Answer 1

Gravitational force

1. Acceleration due to gravity, $g=\frac{GM}{r^2}$ where $G$ is the gravitational constant, $M$ is mass of earth and $r$ is the distance.
2. From the equation, we see that acceleration due to gravity does not depend on the mass of an object.
3. Therefore body with heavier and lighter mass will have the same acceleration due to gravity.
4. We know, that both heavier and lighter objects have the same acceleration due to gravity irrespective of their mass. Hence, they will fall at the same speed.

Air resistance

1. Another quantity that affects the speed of falling objects is air resistance, for lighter objects, air resistance will be high and for heavier objects, air resistance will be low.
2. Air resistance of a body is very less compared to gravitational force.
3. The smaller the mass of an object, the more air resistance will affect it.
4. In the case of bodies will a small difference in mass, the difference in air resistance will be very less and may appear to fall at the same speed.

Heavier objects hit the ground first as they have very less air resistance.