Physics

A driver of a car that is going 25 m/s suddenly notices a train blocking the road. At the instant the brakes are applied, the train is 60 m away. The car decelerates uniformily and stikes the train 3 secs later. (a) How fast was the car moving on impact? (b) What was the magnitude of its acceleration during the 3 secs?

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asked by Addie
  1. d = Vo*t + 0.5at^2 = 60m/s.

    25*3 + 0.5a(3)^2 = 60,
    75 + 4.5a = 60,
    4.5a = -15,
    a = -3.3333m/s^2.

    Vf = Vo + at = 25 + (-3.3333)3 = 15m/s.

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    posted by Henry

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