Question

A car is moving with speed of 150 km/h and after applying the break 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

$\begin{array}{l} F_Rd=\frac{1}{2}mv^2\\\\\frac{d_2}{d_1}=\left(\frac{v_2}{v_1}\right)^2=\left(\frac{1}{3}\right)^2\\\ d_2=d_1\times\frac{1}{9}=3m\end{array}$