A particle of mass M is released in vertical plane from a point P at x = x0 on the axis it falls vertically
along the y-axis. Find the torque τ acting on the particle at a time t about origin?
Torque is produced by the force of gravity.
→τ=r F sin θ ^k or
As r sin θ =x0
As r⊥ F
|→τ|=x0 mg
→τ=mg x0 ^k