Question

A bus decreases its speed from 80km/h to 60km/h in 5 seconds . Find the acceleration of the bus. ( Hint: convert 80km/h to m/s)​

Answer 1

Explanation:

v = u + at

v= 60km/h =50/3 m/s

u = 80km/h =200/9 m/s

a= v-u/t

a =(50/3 - 200/9)/5

a = -10/9 m/s^2

Acceleration is negative because the vehicle reduces it's speed and it is retardation.

Answer 2

80× 1000/3600

= 80× 5/18

= 400/18 m/s

60 × 5/18

= 300/18

a= v- u / t

a= 400/18-300/18 /5

10/9 m/s^2.

ans.