Tension or Compression: Determining the Forces on a Hinged Support Point

[tonald]

The figure shows a weight W supported by two light rigid rods P and Q. The rods are smoothly hinged to the wall and mounted in the same vertical plane. Which rod is in compression , is in tension?

 

[Doc Al]

Show what you've done so far and where you got stuck.

 

[tonald]

I can't think anything...
Actually, compression means the force towards the wall?
Can you give me some hints to start with the question...

 

[Doc Al]

"Compression" means that there's an inward force pushing on the ends of the rod; "tension" means there's an outward force on the rod.

This is a problem in static equilibrium.

 

[tonald]

Can you show me how to solve this question...
I really can't solve it
or please give me some hints to guide me to finish it ,thanks...

 

[tiny-tim]

Welcome to PF!

The figure shows a weight W supported by two light rigid rods P and Q. The rods are smoothly hinged to the wall and mounted in the same vertical plane. Which rod is in compression , is in tension?

Hi tonald! Welcome to PF!

Hint: use good ol' Newton's second law on the peg (or whatever it is) where the two rods meet …

it isn't moving, and there are three forces on it, so they … ?