finding the average force of the Helicopter

Question

An attack helicopter is equipped with a 20-
mm cannon that fires 129 g shells in the
forward direction with a muzzle speed of
1030 m/s. The fully loaded helicopter has
a mass of 3170 kg. A burst of 223 shells is
fired in a 2.87 s interval.
What is the resulting average force on the
helicopter?
Answer in units of N.

Answer 1

let m = mass of each shell = 129g = 0.129 kg

let v = muzzle speed = 1030 m/s

let Δt = 2.87 s

change in momentum due to each shell = Δ(mv)

= Impulse = FΔt

(0.129)*(1030) = 132.87 = F (2.87)

F = 132.87/2.87 = 46.296 N