## Chemistry 12th Edition

Let us assume that on stopping the car, its K.E is converted to frictional heat that is $q=\frac{1}{2}mv^2$ We know that the amount of generated is directly proportional to braking distance. Mathematically, we can express it as $d \space \alpha \space q$ and $d \space \alpha \space v^2$ That's why , when v increases to 2v, d becomes four times.