A policeman investigating an accident measures the skid marks left by a car on the horizontal road. He determines that the distance was 23.7

Question

A policeman investigating an accident measures the skid marks left by a car on the horizontal road. He determines that the distance was 23.74 n. The coefficient of kinetic friction between the tires and the road is μk = 0.29 How fast was the car going when the driver applied the brakes

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Đan Thu 4 years 2021-09-02T18:17:11+00:00 1 Answers 30 views 0

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  1. Neala
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    2021-09-02T18:18:47+00:00
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    The velocity of car was m m/s

    Explanation:

    When the car skids , its centripetal force is provided by frictional force .

    Here centripetal force F = \frac{mv^2}{r}

    here v is the velocity of car and r is the radius of the curve .

    The frictional force f = μ R

    here μ is the coefficient of kinetic friction and R is normal reaction

    Thus f =  m g

    On horizontal road R = mg

    Thus F = f  at the time of skid .

    Thus v = \sqrt{\mu rg}

    = \sqrt{0.29x23.74x10} = 9 m/s

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