# Homework Help: Torque and equilibrium problem

1. Nov 2, 2008

### Kingrick

1. The problem statement, all variables and given/known data
for the 1m long, 5N beam below, find the balancing mass m and the supporting tension T

T
----- ^
| | | ------
| m | |(25cm) | 2kg |
---------------------------------(1m)

2. Relevant equations

f=ma

torque= Fxr
cross product, F x rsinx

3. The attempt at a solution

first i summed the forces

Fx=0, no forces acting in x.

Fy=0

forces acting

1. m1g= 9.8m1
2> m2g= 19.6N
3. CG= 5n
4. T =?

9.8m1 + 19.6N + 5N - T= 0

so T = 9.8m1 + 24.6N

next I summed the torques

19.6N * 0.75m + 5 * 0.25 -(9.8)(.25m)m1 = 0

m1 = 6.5kg

Fm1= 63.7N

the actual answer of the force is -88.7N, and the T=8.45

seeing how i have the wrong force values i know that my T will be wrong using it. if anyone can show me where I went wrong in this one that would be very helpful thanks.

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2. Nov 2, 2008

### Kingrick

sorry about picture, i just uploaded a paint file so hopefuly that works.

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