Answer
$I=15KN\cdot s$ in both cases
Work Step by Step
The required impulse can be determined as follows:
We apply the principle of impulse and momentum in the x-direction
$mv_{x_1}+\Sigma \int F_xdt=mv_{x_2}$
We plug in the known values to obtain:
$20000(0.75)-\int F_x dt=0$
This simplifies to:
$I=15KN\cdot s$
