Question

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

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

Answer 1

The correct option is D 1 : 16

$a=\mu g$
For 1st car For 2nd car
$0-u^2=–2\left(\mu g\right)S_1$ $0-(4u{)}^2=-2\mu g{S}_2$
$\therefore S_1=\frac{u^2}{2\mu g}$ $\therefore S_2=\frac{16u^2}{2\mu g}$
$\Rightarrow S_2=16.S_1$