The smooth ring A can slide on a fixed horizontal rod as shown the pulley is fixed. If some instant velocity of ring is v, find the velocity of block at that instant.

Explanation

length of the sting
`L=(x^(2)+h^(2))^(1//2)+y=` constant
`(dL)/(dt)=(1)/(2)(x^(2)+h^(2))^(-1//2)(2x(dx)/(dt)+0)+(dy)/(dt)`
[As L ad h are constant `(dL)/(dt)=0,(dh)/(dt)=0]`
`0=(x(-v))/(sqrt(x^(2)+h^(2)))+v_(B)`
`v_(B)=vcosalpha`