Question

A bus decreases its speed from 80km/h to 60km/hin 5s. Find the acceleration of the bus.(acceleration=final velocity - initial velocity /time)

Answer 1

Acceleration is rate of change of velocity.
here, initial velocity= 80 Km/h= 22.2 m/s
final velocity= 60 Km/h= 16.6 m/s
change in velocity = final velocity- initial velocity= 22.2-16.6= 5.6 m/s
Now, acceleration= change in Velocity/ time
so, acceleration= 5.6/5= 1.12 m/s^2.

Answer 2

acceleration = change in velocity/time
=(final velocity-initial velocity)/time

Final velocity = 60km/h =60×5/18 m/s
Initial velocity = 80km/h = 80×5 /18 m/sec

So,
Acceleration= (60 - 80)×5/18 /(5)

= - 20/18 m/s²