# Physics/Mechanics Equilibrium Force Question

1. Sep 9, 2010

### bob29

1. The problem statement, all variables and given/known data
Find the reaction forces of A and B.
Uniform bar with a mass of 100kg/m supported by a pin and a roller.
$$\Theta$$ = 60
g=9.81m/s2
[URL]http://img340.imageshack.us/i/mechanicsproblem.jpg/[/URL]
http://img340.imageshack.us/i/mechanicsproblem.jpg/

2. Relevant equations
Moment/torque = Force*Displacement
Sum of MA=0 (moment about point A)
Sum of FY=0
Sum of FX=0

3. The attempt at a solution
Taking M about point A. (Counter-clockwise as +ve)
9BY - (1500N*7m) - (2400N*sin(60) * 3.5m) - [100kg/m*9m*9.81m/s2*(1/2*9m)]=0
9BY = 57,505N
BY = 6.389kN
B = 6.389kN

Sum of FY=0
AY + BY - 2.4kN*sin(60) - 1.5kN - (W=8.829kN) = 0
AY = 6.018kN

Sum of FX=0
AX - 2.4kN*cos(60) = 0
AX = 1.2kN
Would like to verify whether my attempt at the question is correct, as well as my free body diagram.

Last edited by a moderator: Apr 25, 2017
2. Sep 10, 2010

### pongo38

A diagram for the question would help.

3. Sep 10, 2010

### pongo38

Sorry, Iv'e just found the link to the figure. Your fbd is not correct at the left hand load. Something missing there. You can check your own work by taking moments about any point other than A.