# Homework Help: Static mechanics problem

1. Apr 26, 2013

### bostonfenway

Thank you so much!

http://imageshack.us/scaled/landing/515/19200619.jpg [Broken]

Last edited by a moderator: May 6, 2017
2. Apr 26, 2013

### tiny-tim

welcome to pf!

hi bostonfenway! welcome to pf!

show us what you've tried, and where you're stuck, and then we'll know how to help!

3. Apr 26, 2013

### SteamKing

Staff Emeritus
First step, figure out the components of P.

4. Apr 27, 2013

### bostonfenway

Thank you for the welcome! :)

This is what I have done so far:

Vertical component = Pcos30 = .866P
Moment arm = 200cos40 = 153.2
Moment= 132.7P (ccw)

Horiz. comp. = Psin30 = .5P
Moment arm = 200 sin40 = 128.6
Moment = -64.3P (cw)

Net moment = 68.4P
Moment arm of P = 68.4

5. Apr 27, 2013

### tiny-tim

hi bostonfenway!

yes that's fine!

(btw, you can check it by seeing it's Pcos20°)

what is worrying you about that?

6. Apr 27, 2013

### bostonfenway

its right? So the answer to part a is 68.4?
What about part b? That worries me..

7. Apr 27, 2013

### tiny-tim

yes
What about part b? That worries me..​

by definition, the total moment (68.4) equals the total force (200) times the moment arm

8. Apr 27, 2013

### bostonfenway

Got it! Thanks tiny-tim :)