# Question on torue(center of mass being important I think)

1. Nov 30, 2011

Question on torque(center of mass being important I think)

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

I have a lab report due tomorrow, and I have it all done except one calculation, but it confuses me.

The center of mass on my meter stick on a stand is 50.1 cm, or .501 meters.

For part B, we changed the pivot point to 30.0 cm(not the center of mass), or .300 meters. then with 3 mass hanging by a rope are added. I understand that torque is force times radius.

The question is what OTHER forces are acting on the system besides the weights we added on, and then find the torque, mass, radius, and distance.

I suppose this is referring to the force of gravity *mass of meter stick with the distance being .501 - .300 = .201 meters. The torque would then be .164675 Nm. Is this right?

2. Relevant equations

sine = 1

3. The attempt at a solution

Last edited: Nov 30, 2011
2. Nov 30, 2011

### Pythagorean

you didn't give any masses. you should also probably be considering the moment of inertia of the meter stick.

3. Nov 30, 2011

Sorry, the mass of the meter stick is 0.0836 kg.

Well, I don't understand how inertia would tie in with finding the torque of the other forces besides the weights on the tension.

Wouldn't it just be mass of meter stick, the distance between the pivot and the center of mass, then to find the force, just 0.0836 kg * 9.8 m/s^2, and then torque is radius*force?

4. Nov 30, 2011

### Pythagorean

Hrmm... that means... is the system in equilibrium (no motion and not sitting with one end touching the floor)? If so, wouldn't the torque on either side of the fulcrum be the same?

5. Nov 30, 2011