Question

A bus decreases speed from 80km/h to 60km/h is 5seconds. Find the acceleration of the bus.
class 9(science) chapter8 MOTION

Answer 1

Explanation:

U= initial velocity= 80 km/h = 22.2 m/s

v= final velocity = 60 km/h = 16.7 m/s

t= time = 5 s

a= acceleration = ?

a=v-u/t

a= 16.7-22.2/5

a= -5.5/5

Therefore, a=-1.1 m/s^2

Hope it helps u...

Answer 2

Answer:

acceleration is define as the rate of change og velocity .

a = vf - vi / time

where a = acceleration (m/s^2)

vf = final velocity ( m/s)

vi = initial velocity (m/s)

t = time taken (s)

As the velocities are given in km/h, we will convert it in m/s by multiplying it by a factor og 5/18 [ 1km = 1000m , 1 hour = 3600 s, so by solving it we get 5/18]

So , vf = 60*5/18 = 16.67 m/s

vi = 80 * 5/18 = 22.2m/s

Hence,

a= 16.67 - 22.2 / 5

a = - 5.56(m/s) / 5(s)

a = - 1.11 m/s^2