A 1200-kg car, initially moving at 20 m/s, comes to a stop at a red light over a time of 3 s from the moment the driver hit the brakes. What

Question

A 1200-kg car, initially moving at 20 m/s, comes to a stop at a red light over a time of 3 s from the moment the driver hit the brakes. What is the impulse delivered to the car by the static friction force (assumed constant) between the road and the tires

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Nguyệt Ánh 4 years 2021-09-02T08:27:46+00:00 1 Answers 72 views 0

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  1. Eirian
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    2021-09-02T08:29:26+00:00
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    Answer:

    Explanation:

    Mass of car (M)=1200kg

    Initial velocity (u)=20m/s

    Stop after time (t)=3sec.

    Come to stop implies that the final velocity is zero, v=0m/s

    Using newton second law of motion

    F=m(v-u)/t

    Ft=m(v-u)

    Since impulse is Ft

    I=Ft

    Then, I=Ft=m(v-u)

    I=m(v-u)

    I=1200(0-20)

    I=1200×-20

    I=-24,000Ns

    The impulse delivered to the car by static friction is -24,000Ns

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