challenge: A 3 kg model airplane is traveling at a speed of 33 m/s ... The operator then increases the speed up to 45 m/s in 2 seconds. How much force did the engine need in order to make this change?

The average force exerted on an object is given by the equation:

F = Δp/Δt = mΔv/Δt = m (Vf-Vi) / Δt

F is the average force, m is the object's mass, Vi is the object's initial velocity, Vf is the object's final velocity, and Δt is the time elapsed.

Given values:

m = 3kg

Vi = 33m/s

Vf = 45m/s

Δt = 2s

Plug in the values and solve for F:

F = 3 (45-33) / 2

F = 18N