Question

A small ball of mass 1.0 kg is attached to one end of a 1.0 m long massless string and te other end of the string is hung from a point O. When the resulting pendulum is making 30^(@)C from the vertical, what is the magnitude of net torque about the point of suspension? [Take g=10m//s^(2)]

Answer 1

Here is your answer:

Explanation:

two forces are acting on the ball

(i) tension (T)l,

(ii) weight (mg)

torque of tension about point O is zero. As it passes through O.

τmg=F×r⊥

Here, r⊥= OP = 1.0sin30∘ = 0.5m ltbr τmg = (mg)(0.5)

=(1)(10)(0.5) =5N−m