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A box of canned goods slides down a ramp from street level into the basement of a grocery store with acceleration 0.82 m/s2 directed down the ramp. The ramp makes an angle of 38° with the horizontal. What is the coefficient of kinetic friction between the box and the ramp?

Respuesta :

Explanation:

The given data is as follows.

     a = 0.82 [tex]m/s^{2}[/tex],      Angle ([tex]\theta[/tex]) = [tex]38^{o}[/tex]

So, in x-direction the force will act on the box. Hence, formula for normal force and x-component of the gravitational force is as follows.

              [tex]F_{n} = mg Cos (\theta)[/tex] ............. (1)

In y-direction,

            [tex]mg sin (\theta) - f = ma[/tex] .............. (2)

and,          f = [tex]\mu_{k} F_{n}[/tex] ........... (3)

Now, we will use equations (1), and (3) in equation (2) as follows.

        [tex]mg sin (\theta) - (\mu_{k} mg cos (\theta)[/tex] = ma

Then,

           [tex]\mu_{k} = \frac{a - g sin (\theta)}{g cos (\theta)}[/tex]

                       = [tex]\frac{9.8 sin (38) - 0.82}{9.8 cos (38)}[/tex]

                       = [tex]\frac{2.9008 - 0.82}{9.359}[/tex]

                       = 0.22

Thus, we can conclude that the coefficient of kinetic friction between the box and the ramp is 0.22.