In the track shown in figure section `AB` is a quadrant of a circle of `1` meter radius. A block is released at `A` and slides without friction until it reaches `B`. After B it moves on a rough horizontal floor and comes to rest at distance `3` meters from B. What is the coefficient of friction between floor and body?

Options

A. `1//3`
B. `2//3`
C. `1//4`
D. `3//8`

Answer

A

Explanation

`mg1=(1)/(2)m u_(2)rArr u_(2)=2g`...(1)
`v_(2) =u_(2)+2as rArr 0=2g-2a(3)`
`rArr a=(g)/(3) rArr mu_(k) g=a`
`:. mu_(k) g = (g)/(3)`
`:. u_(k) = (1)/(3)`