Question

The break of a car can slow it down from 60 miles per hour to 40 miles per hour in two secs how long it bring the car to a stop from an initial velocity of 25 miles per hour at the same acceleration

Answer 1

a = (60-40)/2 = 20mi/hr-s
So, to decelerate from 25 mi/hr to zero, it will take

(25mi/hr)/(20mi/hr-s) = 1.25s

Answer 2

(60-40)/2 = 20/2 = 10
so I get 2.5 seconds