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Question
A train moving with a velocity of 20 ms−1 is brought to rest by applying brakes in 5 s. Calculate the retardation.
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Solution
Given:
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Initial velocity, u = 20 m/s
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Final velocity, v = 0 m/s (since train comes to rest)
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Time, t = 5 s
0 = 20 + a × 5
0 = 20 + 5a
5a = −20
a = −4m/s2
Retardation = 4 m/s2
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