Question

How long does it take to accelerate an object at rest to 15m/s if the acceleration was 3m/s2?

Answer 1

Answer:

First of all, we'll use the formula,

v^2 = u^2 +2as; where, v = final velocity = 15 m/s(given), u = initial velocity = 0 m/s, a = uniform acceleration = 3 m/s^2 (given), & s = distance covered by the object in the required time.

=> 15^2 = 0+2×3×s

=> s = 225/6

Now, from the formula,

s = ut + (1/2)×a×t^2(where, t is the required time), we get,

225/6 = 0×t + (1/2)×3×t^2

=> t^2 = 225/9

=> t = 15/3

i.e., t = 5 s. (Ans)

Hope, it'll help..!!

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