# Homework Help: Equillibrium: torque and net force

1. Mar 3, 2015

### henry3369

1. The problem statement, all variables and given/known data
http://imgur.com/rWsNsmp [Broken]

2. Relevant equations
net torque = 0
net force = 0
3. The attempt at a solution
Finding f1 was easy.
f1 = wladder + person = 885.92 N
Then the horizontal forces are also equal:
f2 = f3

Now net torque = 0 (I'm using moment arm because there is no angle given):
f3(3.8) = wladder(moment arm) + wperson(0.70)

I can't manage to figure out the moment arm. I'm not sure if 0.7 meters can be used because I think that is the moment arm for the force of the person only. No angles were given, all I know is that the distance from the bottom of the ladder to the center of mass of the ladder is 2 meters.

Last edited by a moderator: May 7, 2017
2. Mar 3, 2015

### Svein

Oh, yes, they were (but indirectly). Length of ladder = 4m, vertical height of ladder = 3.8m.

3. Mar 3, 2015

### henry3369

Didn't think about it that way. Thanks!