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

$(a)$ What do you mean by free fall?
$(b)$ What happens to the direction of motion of objects during free fall?
$(c)$ $A$ stone is dropped from a height of $19.6 \, m$. Calculate:
$(i)$ Time taken to fall.
$(ii)$ How fast does it move at the end of this fall?
$(iii)$ Acceleration after $1 \, s$.

The acceleration due to gravity on the surface of the Earth is:

At which of the following locations is the value of $g$ maximum?

The equation $F = G \frac{m_1 m_2}{r^2}$ is valid only for:

What is the effect on the weight of a body due to the revolution of the earth?