A racetrack has the shape of an inverted cone, as the drawing shows. On this surface the cars race in circles that are parallel to the ground, and the surface is at an angle = 20°. For a speed of 29 m/s, at what value of the distance d should a driver locate his car if he wishes to stay on a circular path without depending on friction?

Question

A racetrack has the shape of an inverted cone, as the drawing shows. On this surface the cars race in circles that are parallel to the ground, and the surface is at an angle  = 20°. For a speed of 29 m/s, at what value of the distance d should a driver locate his car if he wishes to stay on a circular path without depending on friction?

John · Accepted Answer

The above solution is correct to find r. We are looking for distance d. r is the adjacent side, so... cosTheta= r/d solve for d

bobpursley · Answer

the force trying to make is slide down is mg*sinTheta. The force making it slide upward is mv^2/r * cosTheta set them equal, solve for r.