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

Options

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

Answer

D

Explanation

Using `v^2 = u^2 + 2as`. If car is retarding and final velocity becomes zero. Then, the equation becomes
`0 = u^2 - 2as rArr s = (u^2)/(2a)` or `s prop u^2`
As `s prop u^2 rArr (s_1)/(s_2) = ((1)/(4))^2 = (1)/(16)`.