The bob rotates in a circular path ,if u=sqrt(7gR)` then lt
(a) What is the velocity at topmost point?
(b) What is tension at topmost point?
(c) What is tension at bottommost point?

Answer

A, B, C

Explanation

(a) `v=sqrt(u^(2)-2gh)=sqrt(7gR-2g(2R))=sqrt(3gR)` ltbr. (b) `T+mg=(mv^(2))/(R)=(m)/(R)(mgR)`
:. `T=2mg`
(c) `T-mg=(mu^(2))/(R)=(m)/(R)(7gR)`
:. `T=8mg`