Question

A moving train is brought to rest within 20 seconds by applying brakes.Find the inital velocity,if the retardation due to brakes is 2m/s^2.

Answer 1

Given : -

• Final velocity of train = 0m/s

•Time taken to brought the train to rest = 20second

•Acceleration of train is = -2m/s^2.

To Find : -

•Initial velocity = ?

Solution : -

Here,

• v = 0
• a = -2m/s^2
• t = 20sec

we have,

$\: \sf \large \: v = u + at$

Now substitute the values

$\: \sf \implies \: 0 = u - 2 \frac{m}{ {s}^{2} } \times 20s \\ \\ \: \sf \implies \: u = 40 \frac{m}{s}$

Thus,the inital velocity of the train is 40m/s.

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