# Urgent help on Mechanics of materials Question..

• posted

hi everybody..

i have a question that must be solved using any computer program..

the question is :

Disks D1, D2, ..., Dn are attached to a fixed ends solid shaft AB of length L, uniform diameter d, and yield stress, Sy. P1, P2, ..., Pn are forces applied to the disks, either at the top or bottom of a vertical diameter, or at the left or right end of a horizontal diameter. They are known except one. Denoting by ri the radius of disk Di and by ci its distance from the support at A, Develop a computer program to calculate the magnitude of the unknown force Pi.

Note: Only one force is applied in each disk and its direction might be in +z,-z or +y,-y .

i know this question is solved using Moment equation by calculation of all moments of the known forces ( moment = force* diameter ) and then equating the resultant moment to the moment of the unknown force to find the force.. but its algorithm seems hard to me as the direction of the forces may give me negative moments or positive moments,thus the resultant moment of the known forces depend on their directions..Can any one help me on that, how to start and what to do ?

Thank you very much, i appreciate you HELP..