- #1
Jordan_
- 20
- 0
Okay, I have uploaded the question to imageshack because it would be to difficult to understand the question without the diagram. Basically, I've done a lot of work on it and know I'm on the right track. If someone could point out where I have made a mechanical error it would be greatly appreciated. The question I am on is number 3.22, the one in the top right corner of the page.
http://img37.imageshack.us/img37/350/phys122yv.jpg
So first off I made a free body diagram. Two Fn's going up, two 150's going down and a 500 going down. I solved for Fn and got 400N.
Then I solved the triangle to find that the angle between the cord and the board is 54 degrees. Finally I did torque calculations as follows:
T1 = 400(Fn) * 3 * sin 36
T1 = -705N
T2 = T * 2.5 * sin 54
T2 = 2.02T
2.02T = 705
T = 349N?
The answer should be 280 Newtons. Where have I gone wrong?
http://img37.imageshack.us/img37/350/phys122yv.jpg
So first off I made a free body diagram. Two Fn's going up, two 150's going down and a 500 going down. I solved for Fn and got 400N.
Then I solved the triangle to find that the angle between the cord and the board is 54 degrees. Finally I did torque calculations as follows:
T1 = 400(Fn) * 3 * sin 36
T1 = -705N
T2 = T * 2.5 * sin 54
T2 = 2.02T
2.02T = 705
T = 349N?
The answer should be 280 Newtons. Where have I gone wrong?