How Does the Angle of a Simple Pendulum Affect Its Torque?

[Kiko:)]

A simple pendulum consists of a 3.0kg point mass hanging at the end of a 2.0m long light string that is connected to a pivot point.
A. Calculate the magnitude of the torque (due to the force of gravity) around this pivot point when the string makes a 5.0 degree angle with the vertical.
B. Repeat this calculation for an angle of 15.0 degrees.



I do know that the torque equation is torque=forcexlever arm. Also that sinO is included. Also that the units for torque are NxM. I'm having some trouble figuring this out. Please help me. :)

 

[tiny-tim]

Hi Kik!

(have a theta: θ )

No, you don't use both lever arm and sinθ, you use one or the other.

Either use force x (perpendicular) distance from pivot to line of force (= lever arm),

or use force x distance from pivot to point of force x sinθ.

(oh, and the unit is m, not M)