Question

A batsman hits back a ball straight in the direction of the bowler without changing its initial speed of $12$ $m{s}^{-1}$. If the mass of the ball is $0.15kg$ the magnitude of the impulse imparted to the ball is

• A. $36kgm/s$
• B. $3.6kgm/s$
• C. $0.36kgm/s$
• D. $0.03kgm/s$

Answer 1

The correct option is B $3.6kgm/s$

Impulse $=$ Change in linear momentum .

Initial momentum of ball $=mu$

$=0.15\times 12=1.8kg.m/sec$

Final momentum of ball $=-mu$

$=-0.15\times 12=-1.8kgm/sec$

Now,

Change in momentum of ball $=$ Final $-$ Initial

$=-1.8-1.8=-3.6kgm/sec$

So,

Change in momentum of bat $=-$ change in momentum of ball

Change in momentum of bat $=3.6kgm/s$

Now,

Impulse imparted to ball $=$ Change in momentum of bat $=3.6kgm/s$