On aircraft carriers, catapults are used to accelerate jet aircraft to flight speeds in a short distance. One such catapult takes a 18,200-kg jet from 0 to 68 m/s in 2.8 s.

Question

(Assume the catapult acts in the positive horizontal direction. )

How far does the jet travel while it is accelerating? (in meters)

How large is the force that the catapult must exert on the jet? (N)

Answer 1

1. How far does the jet travel while it is accelerating? (in meters)

Use x_f = x_i + v₀*t+(1/2)*a*t²

The initial velocity and the initial position are zero!

x_f = 0+0+(1/2)*a*t², so x_f = (1/2)*(68 m/s - 0 m/s)*(1/2.8s)*(2.8s)^2 = 95.2 m

1. How large is the force that the catapult must exert on the jet? (N)

F = m*a, Force = mass*acceleration, so F = (18,200 kg)*(68 m/s - 0 m/s)*(1/2.8s) = 4.42*10^5 N