Question

a rubber ball of 20 g is attached to a string of 0.8 cm length if the ball is swung in a horizontal circle making 1 revolution in 0.9 seconds find the speed of the ball and the centripetal acceleration and centripetal Force

Answer 1

The speed:

$$v=\frac{2\pi r}{T}=\frac{2\pi·0.008\text m }{0.9\text s}=0.056\text{ m/s}.$$

The centripetal acceleration:

$$a_c=\frac{v^2}r=0.39\text{ m/s}^2.$$

The centripetal force:

$$F_c=ma_c=7.8·10^{-3}\text{ N}.$$