Question

    Starting from a stationary position, Rahul pedals his

    bicycle to attain a velocity of 6 ms⁻¹ in 30 s. Then he applies brakes such that the velocity of the bicycle comes down to 4 ms⁻¹ in the next 5 s. Calculate the acceleration of the bicycle in both the cases.
    A 0.2 ms⁻² and – 0.4 ms⁻² Correct Answer Incorrect Answer
    B 1.5 ms⁻² and 4 ms⁻² Correct Answer Incorrect Answer
    C 0.8 ms⁻² and – 0.6 ms⁻² Correct Answer Incorrect Answer
    D More than one of the above Correct Answer Incorrect Answer
    E None of the above Correct Answer Incorrect Answer

    Solution

    • For the first case (acceleration while speeding up): o Initial velocity (u) = 0 m/s (stationary) o Final velocity (v) = 6 m/s o Time (t) = 30 s o Acceleration (a) = (v - u) / t = (6 m/s - 0 m/s) / 30 s = 0.2 m/s² • For the second case (deceleration while slowing down): o Initial velocity (u) = 6 m/s o Final velocity (v) = 4 m/s o Time (t) = 5 s o Acceleration (a) = (v - u) / t = (4 m/s - 6 m/s) / 5 s = -0.4 m/s² (negative because it’s deceleration)

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