# Simple Forces Problem

I am studying for the FE exam and came to this problem:

A circular rod of 1in. cross-section area is subjected to several forces. Determine the displacement relative to C (in the attachment). Assume E =29x10^6 psi.

my solution is:

del=1/29x10^6(Fa-b(10in)/1in+Fc-b(8in)/1in)

yet I don't know how to get the right forces Fa-b and Fc-b

signed,

Mental Block

## Answers and Replies

tiny-tim
Homework Helper
Welcome to PF!

A circular rod of 1in. cross-section area is subjected to several forces. Determine the displacement relative to C (in the attachment) …

Hi nikkelm! Welcome to PF!

erm … no attachment … !

Actually, it takes ages to get an attachment approved.

It'll be much quicker if you just describe the picture to us in words!

Oh... I guess that's for copy right infringement stuff... anyways, the cylinder axis is oriented horizontally and it is 18 in long from A to C and 10 inches long from A to B. A is at the left C at the far right with B in the middle, of course. The force at A is 2kip to the left. The force at B is 4kip to the right. The force at C is 4kip to the left again.

PhanthomJay
Homework Helper
Gold Member
Before you go too far, I think you mean the force at C is 2K to the left, or else you're not in equilibrium.

nvn
Homework Helper
nikkelm: Once you resolve the equilibrium issue, you could perform a section cut anywhere you wish, then solve for the unknown force acting on your free-body diagram, to obtain the force in each segment.

That explains things.. there is an error in the problem because it definitely shows a 4kip force

nvn