Speeds of two identical cars are u and 4u at a specific instant. The ratio of the respective distances in which two cars are stopped from that instant.

Options

A. `1:1`
B. `1:4`
C. `1:8`
D. `1:16`

Answer

D

Explanation

`v ^(2) -u ^(2) = 2d, v =0`
`therefore = ((0)^(2) - u ^(2))/( 2a)`
`therefore d =- ( u^(2))/( 2a),` here `-(1)/(2a) ` is constant.
`therefore d alpha u ^(2)`
`therefore (d _(1))/(d _(2)) = ((u _(1))/( u _(2)))^(2) = ((u)/( 4u )) ^(2)`
`therefore (d _(1))/(d_(2)) = (1)/(16)`
`therefore d _(1) : d _(2) =1 :16`