lasses are canceled due to snow, so you take advantage of the extra time to conduct some physics experiments. You fasten a large toy rocket

Question

lasses are canceled due to snow, so you take advantage of the extra time to conduct some physics experiments. You fasten a large toy rocket to the back of a sled and take the modified sled to a large, flat, snowy field. You ignite the rocket and observe that the sled accelerates from rest in the forward direction at a rate of 12.512.5 m/s2 for a time period of 3.303.30 s. After this time period, the rocket engine abruptly shuts off, and the sled subsequently undergoes a constant backward acceleration due to friction of 5.655.65 m/s2. After the rocket turns off, how much time does it take for the sled to come to a stop?

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Delwyn 4 days 2021-07-19T17:06:20+00:00 1 Answers 3 views 0

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    2021-07-19T17:08:11+00:00

    Answer:

    t = 7.3 s

    Explanation:

    First we consider accelerated motion and use first equation of motion:

    Vf = Vi + at

    where,

    Vf = Final Velocity = ?

    Vi = Initial Velocity = 0 m/s

    a = acceleration = 12.5 m/s²

    t = time for acceleration = 3.3 s

    Therefore,

    Vf = 0 m/s + (12.5 m/s²)(3.3 s)

    Vf = 41.25 m/s

    Now, we consider the decelerated motion and use first equation of motion again:

    Vf = Final Velocity = 0 m/s (since, sled will finally stop)

    Vi = Initial Velocity = Vf of accelerated motion = 41.25 m/s

    a = deceleration = -5.65 m/s²

    t = time taken to stop = ?

    Therefore,

    0 m/s = 41.25 m/s + (-5.65 m/s²)t

    t = (41.25 m/s)/(5.65 m/s²)

    t = 7.3 s

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