**1.** Two spherical balls of mass $10$ kg each are placed $10$ cm
apart. Find the gravitational force of attraction between
them.

Gravitational force of attraction $\\$ F = $\frac{GMm}{r^2}$ $\\$ $\frac{6.67\times 10^{-11} \times 10 \times 10}{(0.1)^2}$ = 6.67 $\times 10^{-7}$ N

**2.** Four particles having masses m, $2$ m, $3$ m and $4$ m are
placed at the four corners of a square of edge a. Find the gravitational force acting on a particle of mass m
placed at the centre.

2 None

Solutions