A car is parked on a cliff overlooking the ocean on an incline that makes an angle of 24.0° below the horizontal. The negligent driver leaves the car in neutral, and the emergency brakes are defective. The car rolls from rest down the incline with a constant acceleration of 3.82 m/s2 for a distance of 60.0 m to the edge of the cliff, which is 50.0 m above the ocean.

Required:
Find the car’s position relative to the base of the cliff when the car lands in the ocean.

Respuesta :

Answer:

The position is  [tex]P = 47.4 \ m[/tex] relative to the base of the ocean

Explanation:

From the question we are told that

    The angle made by the incline with the horizontal is [tex]\theta = 24.0 ^o[/tex]

    The constant acceleration is [tex]a = 3.82 \ m/s^2[/tex]

    The distance covered is [tex]d = 60.0 \ m[/tex]

    The height of the cliff is [tex]h = 50 .0 \ m[/tex]

The velocity of the car is mathematically represented as

      [tex]v^2 = u^2 + 2ad[/tex]

The initial velocity of the car is  u= 0

So

     [tex]v^2 = 2ad[/tex]

substituting values

     [tex]v^2 = 2 * 3.82 * 60[/tex]

    [tex]v = 21.4 \ m/s[/tex]

The vertical component of this velocity is

    [tex]v_v = -v * sin(\theta )[/tex]

substituting values

    [tex]v_v = -21.4 * sin(24.0)[/tex]

    [tex]v_v = -8.7 \ m/s[/tex]

The negative sign is because is moving in the negative direction of the y-axis

The horizontal  component of this velocity is

     [tex]v_h = v * cos (\theta)[/tex]

    [tex]v_h = 21.4 * cos (24.0)[/tex]

    [tex]v_h = 19.5 \ m/s[/tex]

Now according to equation of motion we have

     [tex]h = v_v*t - \frac{1}{2} * g t^2[/tex]

substituting  values

    [tex]50 = -8.7 t - \frac{1}{2} * 9.8 t^2[/tex]

    [tex]4.9t^2 +8.7t -50 = 0[/tex]

using quadratic equation we have that

  [tex]t_1 = 2.42\ s \ and\ t_2 = -4.20\ s[/tex]

given that time cannot be negative

      [tex]t = 2.42 \ s[/tex]

The  car’s position relative to the base of the cliff when the car lands in the ocean is mathematically evaluate as

           [tex]P = v_h * t[/tex]

substituting values

          [tex]P = 19.5 * 2.43[/tex]

         [tex]P = 47.4 \ m[/tex]