posted by Matt .
We consider a man of mass m = 84 kg as shown in the figure below using crutches. The crutches each make an angle of θ = 26degrees with the vertical. Half of the person's weight is supported by the crutches, the other half is supported by the normal forces acting on the soles of the feet. Assuming that the person is at rest, find the magnitude of the force supported by each crutch.
Let the force on each crutch be C Newtons.
m=mass of person kg
g=acceleration due to gravity m/s/s
Resolve all forces acting on the person in the vertical direction,
Forces from soles + forces from crutches = weight
(1/2)*mg + 2*C*cos(26°) = mg