Answer:
Option (a)
Explanation:
Impulse is defined as the change in momentum of the body. It is a vector quantity and its SI unit is Kg m/s.
mass of ball, m = 0.4 kg
initial velocity, u = - 30 m/s
Final velocity, v = + 20 m/s
Initial momentum, pi = mass x initial velocity = m u = 0.4 x (- 30) = - 12 kg m/ s
Final momentum, pf = mass x final velocity = mv = 0.4 x 20 = 8 Kg m /s
Change in momentum = final momentum - initial momentum = 8 - (- 12 )
So, impulse = 20 kg m /s right
Option (a) is correct