Strength of material, how to know it is compressio or tension?

[aiklone1314]

Homework Statement

May i know how to know boom and rod, which is in tension and compression?
http://img7.imageshack.us/img7/5728/16203309.gif
http://img7.imageshack.us/img7/2595/57134603.gif

Homework Equations

The Attempt at a Solution

 

[CFDFEAGURU]

The answer is right in front of you. Look at the directions the forces are acting on each part.

Thanks
Matt

 

[CJSGrailKnigh]

When you're asking for the strength do you mean the Young's Modulus because I don't see enough information to calculate stress and certainly not strain.

 

[CFDFEAGURU]

...Young's Modulus because I don't see enough information to calculate stress and certainly not strain.

This is just a force balance problem in statics. You arent required to calculate the stresses and/or strains.

You could easily calculate the stress in the rod if you wanted to because the diameter of the rod is given.

Thanks
Matt

 

[aiklone1314]

The answer is right in front of you. Look at the directions the forces are acting on each part.

Thanks
Matt

i know, but the question is at first comes without the second picture i had uploaded rite?
then how can i know whether it is compression or tension with just the question(the 1st pic i uploaded)?

 

[pongo38]

Imagine the behaviour of the structure if CB is cut. What happens to the distance CB?