A car moving with a speed of `50 "km.h"^(-1)` can be stopped by brakes after at least 6 m. What will be the minimum stopping distance, if the same car is moving at a speed of `100 "km.h"^(-1)`?

Explanation

Final velocity v=0 , if u = initial velocity, a = retardation and s = distance travelled after applying the brakes then `v^(2)=u^(2)-2as " ""or", 0 = u^(2)-2as " ""or", s = (u^(2))/(2a)`. In this example a is the maximum retardation produced by the brakes .
`(s_(1))/(s_(2))=(u_(1)/(u_(2)))^(2)" ""or",s_(2)=s_(1)((u_(2))/u_(1))^(2)=6xx((100)/(50))^(2)=24`m