# Homework Help: Find tension force of a cable and components of reaction force of pivot

1. Jul 21, 2012

### kurispice

1. The problem statement, all variables and given/known data

Please see attached photos. I've been drawing and re-drawing diagrams but I'm at a loss. For part a, I've tried a right triangle using the top cable as the hypotenuse. I've tried the force equation (ƩF=ma) but I don't think that's right. I just can't get a start.

2. Relevant equations

See attached photo with help describing situation. Note also the angle ∅ has been changed from the book's problem from 65 to 55 degrees.

3. The attempt at a solution

I've started a diagram but I do not know what formulas to use for the math.
If you could walk me through the problem that would be great! I have an exam coming up in two days and have no other help in between.

#### Attached Files:

File size:
21.3 KB
Views:
260
File size:
14.5 KB
Views:
230
• ###### IMAG0356-1.jpg
File size:
16.8 KB
Views:
285
2. Jul 21, 2012

### Villyer

You need to use torque to find the tension in the wire, none of your work or what you mentioned seems to point to using torque.

3. Jul 22, 2012

### kurispice

How do I use torque without knowing the distance in this formula? torque=F times distance
Also, how do I draw a diagram for each part of the problem?

4. Jul 22, 2012

### Villyer

Use $\ell$ in your formulas, since they don't give you a length most likely it will drop out.

For a diagram, draw the rod and label all forces on it, with the angles included. They more or less gave you a diagram, so all thats left to do it label the forces and angles more clearly.

5. Jul 22, 2012

### kurispice

Okay, thanks so much!!!
I'll try that now.