Solution :
Given :
Mass of the baseball, m = 200 g
Velocity of the baseball, u = -30 m/s
Mass of the baseball after struck by the bat, M = 900 g
Velocity of the baseball after struck by the bat, v = 47 m/s
According to the conservation of momentum,

(900 x 47) + (200 x -30) = (900 x
) + (200 x
)
36300 = (900 x
) + (200 x
)
..............(i)


The mathematical expression for the conservation of kinetic energy is

................(ii)

Substituting (i) in (ii)




Solving the equation, we get

The negative velocity is neglected.
Therefore, substituting 96 m/s for
in (i), we get

= 19
Thus, only impulse of importance is used to find final velocity.