A car starts from rest on a `1600 m` long bridge. The coefficient of friction between the tyre and road is `0.8`. The minimum time taken by the car to cross the bridge is

Options

A. `5 s`
B. `10 s`
C. `15 s`
D. `20 s`

Answer

D

Explanation

The maximum acceleration possible on rough horizontal surface `= mu g`
`s = (1)/(2) at^(2) rArr t = sqrt((2 s)/(a)) = sqrt((2 xx 1600)/(0.8 xx 10))`
`t = 20 s`