Question

A juggler is throwing balls vertically upward in such a way that the next ball is thrown when the previous one is at the maximum height. If the maximum height is 5 m, the number of balls thrown per minute will be

• A. $15$
• B. $30$
• C. $60$
• D. $20$

Answer 1

Answer: (C)

$60$

Maximum height reached $H=5m$

Initial velocity $u=\sqrt{2gH}=\sqrt{2\times 10\times 5}=10m/s$

Time taken to reach the maximum height $t=\frac{u}{g}=\frac{10}{10}=1s$

Since, the balls are thrown after every 1 second. So, $60$ balls are thrown per minute.