No Response to Physics Homework Help: X-Components of Reaction

[jehan60188]

tried posting in homework help, but haven't received a response
would appreciate any input!

original topic: https://www.physicsforums.com/showthread.php?t=584077

the problem: http://desmond.imageshack.us/Himg839/scaled.php?server=839&filename=truss1.png&res=medium

i can't figure out how to get the x-components of the reaction
thanks!

 

[OldEngr63]

This requires that you know how to read the universal code used by professors and textbook authors. This is secret, so do not tell anyone what I am about to divulge to you here.

The left hand end at A is supported on rollers, but the right end is supported on a solid support to ground. This means that there can be no horizontal reaction force at A but there can be at the right end. There for the entire reaction to all applied horizontal forces is taken out at the right end.

In actual fact, this is not as mysterious as it looks. Actual strictures, such as bridges, etc. are built with only one fixed point, and the other horizontal supports are on rollers.

 

[jehan60188]

Ah, didn't notice the roller joint, makes this problem a lot easier, thanks!