Question

A hockey player receives a corner shot at a speed of 15 m/s at angle 30${}^o$ with y-axis and then shoots the ball along x-axis with the speed 30 m/s. If the mass of the ball is 150 g and it remains in contact with the hockey stick for 0.01 s, the force exerted on the ball along x-axis is :

• A. 281 N
• B. 187.5 N
• C. 562.5 N
• D. 375 N

Answer 1

The correct option is C 562.5 N

Mass of the ball $m=150$ gm $=0.15kg$

Initial velocity of the ball $u=30$ $m/s$

Final velocity of the ball $v=15$ $m/s$

$\therefore$ Change in momentum of ball along x-axis $\Delta P=mv-m(-usin{30}^o)$

$\Delta P=mv+musin{30}^o$

$\Delta P=0.15\times 30+0.15\times 15\times 0.5$ $⟹\Delta P=5.625$ $kgm/s$

Force exerted on the ball $F=\frac{\Delta P}{\Delta t}=\frac{5.625}{0.01}=562.5$ N