posted by Anonymous on .
An attack helicopter is equipped with a 20-
mm cannon that ﬁres 198 g shells in the
forward direction with a muzzle speed of
711 m/s. The fully loaded helicopter has a
mass of 4810 kg. A burst of 75.3 shells is ﬁred
in a 6.27 s interval.
What is the resulting average force on the
Answer in units of N
The fired shells exert a backward force on the helicopter that equals the rate that forward momentum is created for the shells.
F = (75.3)(0.198)*(711)/6.27 = 1691 N
kg*m/s*(1/s) = Newtons