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Basics physic/statics question


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In regards to drawing free body diagrams and solving for unknown forces on a basic beam type problem:

I understand that roller supports will result in only one reaction force on the beam, perpendicular to the surface the roller is resting on. I intuitively think that the reaction force must be away from the surface.  However, DD recently had a homework question where the correct answer given had the reaction force "into" the roller support.  Is this possible and can you explain it conceptually?

I added the problem as an image if that would help.

EF HW.pdf

Edited by Pegasus
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I don't understand these symbols. What is B? Can the force at B be at an angle? Somewhere there must be a force component to the right for the beam to be in equilibrium.

But if you just consider the torques about point B, then the CW torque from the 620N force is much bigger than the very small CCW torque from the 340 N force, so the torque from the force at A has to be CCW which means the angle must be larger than 180. I don't understand the definition  of their "roller support" as I have never come across this term - but if this thing is in equilibrium, the force has to be directed down. Since this seem to be computer generated numbers, it is entirely possible the computer system has created a physically impossible scenario.


Edited by regentrude
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