A bus decreases its speed from `80 km//h` to `60 km//h` in `5 s`. Find the acceleration of the bus.

Explanation

Here, initial speed, `u = 80 km//h = (80 xx 1000m)/(60 xx 60 s) = 22. 22 m//s`
final speed, `v = 60 km//h = (60 xx 1000 m)/(60 xx 60 s) = 16.66 m//s`
time taken, `t = 5 s`
Acceleration, `a = (v -u)/(t) = (16.66 -22.22)/(5) = (-5.56)/(5)= -1.11 m//s^(2)`
Negative sign is for retardation.