Question

If the speed of car is reduces from 108km/hr to 36km/hr in 4 sec calculate acceleration

Answer 1

First we need to convert the speed into   meter/second, to do it we need to divide the speed by 5/18.

108km/hr = (108*5)/18

                  =30m/s

36km/hr  = (36*5)/18

                  =10m/s

Acceleration =  change in speed / time

                       = (30-10)/4

                       = 20/4

                       = 5m/s*s