Question

Review Concept Simulation 9.2 and Conceptual Example 7 as background material for this problem. A jet transport has a weight of 2.79 x 106 N and is at rest on the runway. The two rear wheels are 15.0 m behind the front wheel, and the plane's center of gravity is 12.5 m behind the front wheel. Determine the normal force exerted by the ground on (a) the front wheel and on (b) each of the two rear wheels. (a) Number Units (b) Number Units

Answer 1

Let Ff and Fb are force exerted fron and rear wheels.
a)
As the jet is in equilibeitum, net force and net torque acting on the jet must be zero.

Apply, net torque about rear wheels = 0

Ff*15 - (15 - 12.5)*2.79*10^6 = 0

Ff = (15 - 12.5)*2.79*10^6/15

= 4.65*10^5 N <<<<<<<<----------------Answer

b)

Apply net torque about fron wheel = 0

12.5*2.79*10^6 - 2*Fb*15 = 0

30*Fb = 12.5*2.79*10^6

Fb = 12.5*2.79*10^6/30

= 1.1625*10^6 N <<<<<<<<----------------Answer