The 'well of death' in a circus consists of a vertical hollow cylinder of radius 9 m A motor cyclist rides on its wall with sufficient speed to prevent him from sliding down . If coefficient of friction is 0.9, the minimum speed the motor cyclist should he is
`(g=10ms^(-2))`

Options

A. `5 ms^(-2)`
B. `10ms^(-1)`
C. `15ms^(-1)`
D. `20ms^(-1)`

Answer

B

Explanation

For the motor cyclist not to skid ,
`mg=m((mv^(2))/(r))`
`impliesv=sqrt((rg)/(mu))=sqrt((9(10))/(0.9))=10 ms^(-1)`.