Question
A simple pendulum of length (l) is pulled aside to make an angle $\theta$ with the vertical. Find the magnitude of the torque of the weight (w) of the bob about the point of suspension. When is the torque zero?
✓
Answer
A simple of pendulum of length (l) is suspended from a rigid support. A bob of weight (w) is hanging on the other point.When the bob is at an angle $\theta$ with the vertical, then total torque acting on the point of suspension = i = F × r
$\Rightarrow\text{Wr}\sin\theta=\text{Wl}\sin\theta$
At the lowest point of suspension the torque will be zero as the force acting on the body passes through the point of suspension.
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