Question

A car is moving with speed of $150\, km / h$ and after applying the brake it will move $27 \,m$ before it stops. If the same car is moving with a speed of one third the reported speed then it will stop after travelling ______$m$ distance.

Answer 1

Stopping distance $=\frac{ v ^2}{2 a }= d$
If speed is made $\frac{1}{3} rd$
$d ^{\prime}=\frac{1}{9} d . \,\,d ^{\prime}=\frac{27}{9}=3$
Braking acceleration remains same