1. The problem statement, all variables and given/known data For part c ii) of this question, the new distance is now 1/4 of the previous distance as both acceleration are the same. But why are both the acceleration the same? 2. Relevant equations v^2= u^2 +2as 3. The attempt at a solution I know that the method is by using the above equation, and taking v as 0, we get s = u^2/2a. So when the initial speed is now halved, we get s' = (u/2)^2 /2a , and ∴ s' = u^2/8a , which is ¼ of the previous distance. But why are the acceleration the same for both cases?