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)`]

Explanation

Two forces are acting on the bll
(i) tension (T)
(ii) weight (mg)
Torque of tension about point O is zero, as it passes through O

`tau_(mg)=Fxxr_(bot)`
Here, `r_(bot)=OP=1sin 30^(@)=0.5 m`
`:. tau_(mg)=(mg)(0.5)=(1)(10)(0.5)=5 Nm`.