A smooth ring of mass `m` can slide on a fixed horizontal rod. A string tied to the ring pases over a fixed pulley B and carries a block C of mass 2m as shown below. As the ring starts sliding
A. The acceleration of the ring is `(2g cos theta)/(1+2 cos^(2) theta)`
B. The acceleration of the block is `(2g)/(1+2 cos^(2) theta)`
C. The tension in the string is `(2mg)/(1+2 cos^(2) theta)`
D. If the block descends with velocity `v` then the ring slides with velocity `v cos theta`