Question

a bus decreases its speed from 80 km per hour to 60 km per hour in 5 second find the acceleration of the bus

Answer 1

u = 80 km/h
= 80×3600/1000
=288 m/s
v = 60 km/h
= 60×3600/1000
= 216 m/s
t = 5 seconds

a = u - v/t
a =288 - 216/5
a = 72/5
a= 14.4 m/s2

Answer 2

Let u be the initial velocity which is given at 80 km/h = 22.2 m/s

Let v be the final velocity which is given at 60 km/h = 16.7 m/s

Let t be the time given at 5 s

Let a be the acceleration where,  

a= v-u/t

a= 16.7-22.2/5

a= -5.5/5

Hence, we get that the acceleration is -1.1 m/s^2