posted by John on .
A plane weighing 220 kN (25 tons) lands on an aircraft carrier. The plane is moving horizontally at 67 m/s (150 mi/h) when its tail hook grabs hold of the arresting cables. The cables bring the plane to a stop in a distance of 84 m. (a) How much work is done on the plane by the arresting cables? (b) What is the force (assumed constant) exerted on the plane by the cables? (Both answers will be underestimates, since the plane lands with the engine full throttle forward; in case the tail hook fails to grab hold of the cables, the pilot must be ready for immediate takeoff.)
Plane's mass M = (220*10^3 N)/g
= 22,450 kg
Initial kinetic energy = (1/2) M V^2
= 5.04*10^7 J
(a) Work done by cables = -(initial KE)
(b) Divide work by distance the plane moves while decelerating. That will be the average force exerted