Question

A bus decreases its speed from 80 km per hour to 60 km per hour in 5 secs. Find the acceleration of the bus.

Answer 1

Heya mate
here is your answer

The negative sign shows that the velocity of bus is decreasing .

I hope this will help you....✌️✌️
thank you:-)

Answer 2

Hey friend,

Here is your answer,
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Time (t) = 5 seconds

Initial speed (u) = 80 km/h

Final speed (v) = 60 km/h

Since the time given is in seconds and converting seconds into hours and then calculating would difficult. So we will convert the speeds in m/s.

u = 80 * 1000     =   200  m/s
             60*60           9

v = 60 * 1000    =   50 m/s
             60*60         3

Acceleration(a) = Final speed(v) - Initial speed(u)
                                            Time(t)

                         = ( 50  -  200 ) 
                               3        9     
                                    5

                         = (150-200)/9
                                     5

                         = -50/9 
                                5

                        = -10    = -1.11.....
                             9

The acceleration of the bus will be -1.11 m/s².

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Hope this helped you !!