Question

A man of mass 60 kg can throw a stone of mass 1 kg upto a height of 5 m. If he is standing on ice skates of negligible mass, the maximum velocity that he can generate in same stone, if he throws it with same force in the horizontal direction is

• A. V_max = 9.9 m/s
• B. V_max = 12 m/s
• C. V_max = 7 m/s
• D. V_max = 10 m/s

Answer 1

The correct option is A

V_max = 9.9 m/s

Velocity of ball = $\sqrt{2gh}$ = 10 m/s

He throws the ball horizontally with same force then suppose his velocity be 'V'

$\therefore$ Applying conservation of momentum ,

60 V = 1 (10 - V)

V = $\frac{10}{61}$ m/s

$\therefore$ $V_{max}$ = 10- V = 10 - $\frac{10}{61}$ = 9.9 m/s