 # How does the force of attraction between `
Question:

How does the force of attraction between two bodies depend upon their masses and distance between them? A student thought that two bricks tied together would fall faster than a single one under the action of gravity. Do you agree with this hypothesis or not? Comment.

Solution:

The force of attraction between two bodies of masses $m_{1}$ and $m_{2}$ and separated by a distance $r$ is given by

$\mathrm{F}=\frac{\mathrm{G} m_{1} m_{2}}{r^{2}}$, where $\mathrm{G}$ is constant.

This force is known as gravitational force. The gravitational force is

1. directly proportional to the product of the masses of two bodies and

2. inversely proportional to the square of the distance between them.

The hypothesis is not correct. This is because, all bodies in the absence of any force of friction fall with the same acceleration (known as acceleration due to gravity) irrespective of their masses. Hence two bricks tied together will not fall faster than a single brick under the action of gravity.