physics

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John is driving at 25m/s. When he brakes, he accelerates at the rate of -5.0m/s^2.

How much time did it take him to stop?
How far does it take him to stop?

  • physics -

    v = Vi + a t
    at end v = 0 so
    0 = 25 - 5 t
    t = 5 seconds

    d = vi t + .5 a t^2
    d = 25(5) - 2.5 (25)
    d = 125 - 62.5
    d = 62.5

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