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A car travels along a semicircular curve, as shown in the figure below. The dashed-line arrow between the car and the center of the circle at r = R corresponds to the r-axis. The static coefficient of friction between the tire and the road is p, = 0.300. The kinetic coefficient of friction is uk = 0.200. At the entrance of the curve the road is perfectly horizontal, and the car moves without slipping at the maximum possible speed. This appears in the top part of the figure. Later on the same curve the road is banked at an angle 8, as shown in the lower part of the figure. If the car continues with the same speed as in the horizontal segment, what is the value of the angle such that the friction force has no component along the r-axis? (In other words, the friction force, if present, is only in the t-direction perpendicular to the screen, so that it does not "help" the car turn around to follow the curved path)



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