In a cargo plane, the center of gravity must be between the front and rear landi
ID: 2065466 • Letter: I
Question
In a cargo plane, the center of gravity must be between the front and rear landing gears in order to maintain a torque equilibrium. The front landing gears help counteract the torque provided by the rear landing gears in this case. A jet transport has a weight of 1.00 106 N and is at rest on the runway. The two rear wheels are 15.6 m behind the front wheel, and the plane's center of gravity is 12.6 m behind the front wheel.(a) Determine the normal force exerted by the ground on the front wheel.
N
(b) Determine the normal force exerted by the ground on each of the two rear wheels.
N
Explanation / Answer
Let normal force on front wheel be Rf and on each of the rear wheels be Rr/2.
Taking moment about front wheel, (Rr/2*2)*17.8 - 106*11 = 0.
So Rr/2 = 309 kN.
Do vertical forces balance, Rf + (Rr/2)*2 = 106.
This gives Rf = 999 kN.
(a) Hence, normal force on front wheel = 999 kN.
(b) Normal force on each of the two rear wheels = 309 kN.