Question

A Navy jet (see the figure) with a weight of 219 kN requires an airspeed of 87 m/s for liftoff. The engine develops a maximum force of 100 kN, but that is insufficient for reaching takeoff speed in the 85 m runway available on an aircraft carrier. What minimum force (assumed constant) is needed from the catapult that is used to help launch the jet? Assume that the catapult and the jet's engine each exert a constant force over the 85 m distance used for takeoff.

Answer 1

V^2 = Vo^2 + 2a*d
a = V^2/2d = 87^2/170 = 44.5 m/s^2.

M*g = 219,000 N.
M = 219000/g = 219000/9.8 = 22,347 kg

F = M*a = 22,347 * 44.5 =

Answer 2

take the answer you get for F and subtract "The engine develops a maximum force of 100 kN" to get the correct answer