# Torque, 2 questions

1. Jun 5, 2009

1. The problem statement, all variables and given/known data
1) In an isometric exercise a person places a hand on a scale and pushes vertically downward, keeping the forearm horizontal. This is possible because the triceps muscle applies an upward force M perpendicular to the arm, as the drawing indicates. The forearm weighs 23.0 N and has a center of gravity as indicated. The scale registers 128 N. Determine the magnitude of M. Distances from the elbow joint (point of rotation) and the muscle: 0.025m ; the cg of the arm: 0.15m ; where the hand rests on the scale: 0.30m
http://www.webassign.net/v4cgiaubel.3@osu/student.pl?l=20090605154839aubel.3@osu1402545781

2)A 1340 N uniform beam is attached to a vertical wall at one end and is supported by a cable at the other end. A W = 2000 N crate hangs from the far end of the beam. The angle from the wall to the beam is 30 degrees, the angle from the cable to the horizontal is 50 degrees. Angle from the box to the bar is 60 degrees.
(a) Calculate the magnitude of the tension in the wire.
(b) Calculate the magnitude of the horizontal and vertical components of the force that the wall exerts on the left end of the beam.
http://www.webassign.net/v4cgiaubel.3@osu/student.pl?l=20090605154839aubel.3@osu1402545781

2. Relevant equations/3. The attempt at a solution
1) I was using the $$E\$$ T= (F1*d1) + (F2*d2) +....+ (Fn*dn) = 0

2) $$E$$T= Tcable*d*sin80-Wb*db*sin60-Wc*dc*sin60
and solving for Tcable
then Fx and Fy I was trying to solve with a similar equation to #1.

I haven't been able to figure out either. Any and all help would be greatly appreciated. I tried to insert the pictures, but for some reason they wont insert them.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution