Question

A stone attached to the end of an inelastic string is whirled round in a circular path of radius 20cm. If the stone makes 15complete revolution in 5secs, calculate it's angular and linear velocity

Answer 1

a) Let's calculate the angular velocity of the stone:

$$\omega=\dfrac{15\ rev}{5\ s}=3\ \dfrac{rev}{s}\cdot \dfrac{2\pi\ rad}{1\ rev}=18.85\ \dfrac{rad}{s}.$$

b) The linear velocity of the stone can be calculated as follows:

$$v=\omega r=18.85\ \dfrac{rad}{s}\cdot 0.2\ m=3.77\ \dfrac{m}{s}.$$

Answer:

a) $\omega=18.85\ \dfrac{rad}{s}.$

b) $v=3.77\ \dfrac{m}{s}.$