Question

A car is moving in a straight line with speed of 18 km/hr.IT is stopped in 5s by applying the brakes.find the speed of car after 2s of applying the brakes?

Answer 1

By applying:                     converting the speed into m/s
V = U + AT                         (18*1000)/(60*60)=5      
We get:                         
0 = 5 + A5
A = -(1)
so the retardation is 1 m/s.
By applying:
V = U + AT
We get:
V  = 5 + (-1)2         (-1) because acceleration is negative 
V = 3
So the speed after 2s would be 3 m/s.