Answer
(a) $I=-1.56\space Kg.m/s$
(b) $F_{avg}=-2535N$
Work Step by Step
(a) We can find the required impulse as follows:
$I=m(v_f-v_i)$
We plug in the known values to obtain:
$I=0.012(0-130)$
This simplifies to:
$I=-1.56\space Kg.m/s$
(b) We can find the required average force as follows:
$v_f^2=v_i^2+2ad$
Putting $v_i=0$ and solving the above equation, we obtain:
$a=\frac{-v_i}{2d}$
$\implies a=\frac{-130}{2(0.04)}$
$\implies a=-211250 m/s^2$
Now $F_{avg}=ma$
We plug in the known values to obtain:
$F_{avg}=0.012(-211250)$
$\implies F_{avg}=-2535N$
