Question

- A bus moving with a velocity of 60 km h is brought to rest in 20 seconds by applying brakes. Find its
acceleration
(Ans. - 0-83 m/s)
A car is retarded by applying brakes at the rate of 2 ms. It is finally stopped in 10 s. Find its initial velocity
(Ans 20 m/s)
A train moving with velocity of 54 km h-' is accelerated so that its velocity becomes 72 km h-in 15 seconds.
Find the acceleration of the train.
(Ans. 033 m/s)
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Answer 1

Answer:

Explanation:

Q.

acceleration= velocity/time

                    = 60/20

                   = 3 km/h

To convert it into m/s multiply 3 by 1000 and divide by 3600.

acceleration= 3000/3600

acceleration  = 0.83 m/s²

Q.

velocity= acceleration×time

             = 2×10

velocity   = 20 m/s

Q.

Suppose final velocity as vₐ and initial velocity as vₓ so now,

vₐ- vₓ/time = acceleration

72-54/15 =

18/15.   =

1.2 km/h = acceleration

Converting into m/s

1.2×1000/3600= acceleration

1200/3600 = acceleration

0.33333 m/s = acceleration