- #1
XxBollWeevilx
- 78
- 0
Homework Statement
A uniform beam of weight w is inclined at an angle [tex]\theta[/tex] to the horizontal with its upper end supported by a horizontal rope tied to a wall and its lower end resting on a rough floor. (a) If the coefficient of static friction between the beam and floor is [tex]\mu_s[/tex], determine an expression for the maximum weight W that can be suspended from the top before the beam slips (W is hanging from a rope at the top of the beam). (b) Determine an the magnitude of the reaction force at the floor and the magnitude of the force exerted by the beam on the rope at P in terms of w, W, and [tex]\mu_s[/tex]. (w is the weight of the beam, W of the mass hanging from the top of the beam...point P is located at the top of the beam where the top of the beam is both connected to the wall and the hanging mass)
Homework Equations
[tex]\Sigma F=0[/tex]
[tex]\Sigma\tau=0[/tex]
The Attempt at a Solution
This problem really confuses me...I suppose the thing that confuses me the most is the location and direction of the reaction forces. I first assumed that the reaction force exerted by the floor would be straight up, but I'm not sure this is the case since the beam is at an angle. Also, would the tension in the upper beam where it is connected to the wall be the reaction force exerted on the rope by the beam?
I also cannot for the life of me determine how the force equations and torque equations are used to determine all of this information. It is in static equilibrium, so the net external force and torque must be zero. But again, I'm having trouble even setting up a force diagram...and I have the system drawn in front of me! The answer given in the book is very complex, but I have no clue how to reach it. Any help would be GREATLY appreciated.
Last edited: