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Eoin asked in Science & MathematicsPhysics · 5 years ago

A 1900-kg car experiences a combined force of air resistance and friction that has the same magnitude whether the car goes up or down a hill?

at 37.6 m/s. Going up a hill, the car s engine needs to produce 52.2 hp more power to sustain the constant velocity than it does going down the same hill. At what angle is the hill inclined above the horizontal? I m very stuck, any help appreciated.

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  • Anonymous
    5 years ago
    Favorite Answer

    52.2hp * 745.7W/hp = 38 925 W

    Since the drag is the same going uphill and downhill, it seems to me that the swing in power is due to the swing in the gravitational force from "against the direction of motion" to "with the direction of motion." If that's true, then

    power P = F * v = (2 * m * g * sinΘ) * v

    38 925 W = 2 * 1900kg * 9.8m/s² * sinΘ * 37.6m/s

    sinΘ = 0.0278

    Θ = 1.59º

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