question_answer

A car travelling at a speed of 30 kmph is brought to rest in 8m by applying brakes. If the same car is travelling at 60 kmph, in what distance can it be brought to halt with the same braking force?

Answer:

\[a=\frac{{{v}^{2}}-{{u}^{2}}}{2s}=\]constant \[S\propto {{V}^{2}}-{{u}^{2}}\Rightarrow \frac{{{S}_{2}}}{{{S}_{1}}}=\frac{v_{2}^{2}-u_{2}^{2}}{{{v}^{2}}-{{u}^{2}}}\,(or)\] \[\frac{{{S}_{2}}}{8}=\frac{{{0}^{2}}-{{60}^{2}}}{{{0}^{2}}-{{30}^{2}}}\] \[\Rightarrow {{S}_{2}}=\frac{60\times 60\times 8}{30\times 30a}=32m\]