A ring of mass m and radius r oscillates in a vertical plane about its topmost point O. The axis is normal to the plane of the ring. Maximum speed of the lowest point P is v.

Select all that apply

• Option A

  Time period for small amplitude is 2π√(2r/g)

• Option B

  Acceleration of the centre of mass at the lowest position is zero

• Option C

  Hinge force at the lowest position is mv²/(4r)

• Option D

  Mechanical energy of oscillation is mv²/4 (taking potential energy at mean position as zero)