Question

A driver decreases the speed of a car from 25 m/s to 10 m/s in 5 seconds find acceleration

Answer 1

U=25m/s
V=10m/s
T=5 sec
We know that
Acceleration = v-u/t
=10-25/5
=-15/5
= -3m/s2
Negative sign shows that car moved in backward direction.(retardation)

Answer 2

Initial velocity = u  = 25m/s
Final velocity = 10 m/s

Time  = t = 10 sec


Acceleration = a  = v-u/t
                        = 10 -25/5
                       = -15/5 = -3 m/s²