A block is gently placed on a conveyor belt moving horizontal with constant speed After `t = 4s` the velocity of the block becomes equal to velocity of the belt If the coefficient of friction between the block and the belt is `mu = 0.2`, then the velocity of the conveyor belt is .

Options

A. `8ms^(-1)`
B. `4ms^(-1)`
C. `6ms^(-1)`
D. `18ms^(-1)`

Answer

A

Explanation

Due to friction `(a-mug)` , veloctiy of block will become equal to velocity of bell . Relative motion between two will stop.
`therefore v=at = mugt = 0.2xx10xx4 = 8ms^(-1)`