Hi there!
Question 1:
We know that Impulse = Δp = mΔv, so:
I = 0.045(70) = 3.15 Ns
I = F · t, so:
3.15/0.1 = F
F = 31.5 N
Question 2.
We can find the impulse using:
I = Ft
I = 300 · 0.04 = 12 Ns
Find the change in velocity using:
I = mΔv
12/0.13 = Δv = 92.31 m/s