Question

4. Find the velocity of the ball when the string makes an angle of 60^o with vertical. The string length is 2m and mass of the ball is 0.05 kg. Initially at the bottom most point the ball is given a velocity of 10 m/sec

Moderate

Solution

We have to apply the work energy theorem. Work done by gravity = change in kinetic energy.
$\begin{array}{l} h = 2 (1 - Cos 60^{\circ}) = 1 m \\ \frac{1}{2} m (10^{2} - v^{2}) = mg \times 1 \\ \Rightarrow v^{2} = 80 \Rightarrow v = 4 \sqrt{5} m / \sec \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

SCAN ME