# Principle of Moments

1. Jan 2, 2015

### Marcus27

1. The problem statement, all variables and given/known data
Calculate the tension in the rope, T, in the diagram below: http://imageshack.com/a/img905/2848/yMC01l.png [Broken]

2. Relevant equations

3. The attempt at a solution
The 'beam' is a stable structure, thus the resultant forces be equal that are acting upon the beam. So,
I calculated the the Torque from the mass as being 150N * 0.6m + 100N * 0.3m = 110 Nm, setting this equal to the Torque generated by the 'force line' from the rope, T*1.2m = 110Nm, thus T rounded to the nearest Newton is = 92N. I Felt fairly confident with this until my textbook said the tension in the rope is = to 100N. Can anybody clear this up for me and explain where I went wrong, Thanks!.

Last edited by a moderator: May 7, 2017
2. Jan 2, 2015

### Bystander

Check your arithmetic, that's "the usual suspect."

3. Jan 2, 2015

### Marcus27

Ah, thank you. I did not spot that mistake, sorry for wasting your time. Not a great first post on my part

4. Jan 2, 2015

### Bystander

Do not let it ruin your day --- we've all been there.