A section of fixed smooth circular track of radius `R` in vertical plane is shown in the figure. A block is released from position `A` and leaves the track at `B` The radius of curvature of its trajectory just after it leaves the track `B` is ?

Options

A. R
B. `(R)/(4)`
C. `(R)/(2)`
D. None of these

Explanation

From energy conservation speed at point B is
`V=sqrt((2gR)/(3))`
`R=(V^(2))/(a_(c))=(29R//5)/(g cos 37)=(R)/(2)`