A 20000 kg airplane takes off by traveling 300 m down a runway while the engines exert a continuous force of 4000 N.(a) Calculate the change in kinetic energy of the airplane during takeoff.(b) Determine the speed of the airplane as it leaves the runway.

Answer 1

Work in = change in Ke = force * distance
= 4000 * 300 = 12*10^5
so
(1/2)(2*10^5) v^2 = 12*10^5

v^2 = 12
v = 2 sqrt3

4,000 N is not enough to get this plane off the ground.