State whether the following statement is True or False:
All objects attract each other along the line joining their centre of mass.

According to Newton's law of gravitation,every particle of matter attracts every other particle. But bodies on the surface of the Earth never move towards each other on account of this force of attraction. Why?

$A$ ball is dropped from a height of $20\, m$. $A$ second ball is thrown downwards from the same height after one second with initial velocity $u$. If both the balls reach the ground at the same time, calculate the initial velocity of the second ball. (Take $g = 10\, m s^{-2}$).

The weight of an object at the centre of the earth of radius $R$ is

Two particles are placed at some distance. If the mass of each of the two particles is doubled,keeping the distance between them unchanged,the value of gravitational force between them will be

Why is the value of $g$ more at the poles than at the equator?