A car turns on a inclined road at a speed of 60 km/h, the mass of the car is 3 tons and the radius of the circular motion is 20m; If there is no friction, calculate the required angle in order to keep the car turning at the same speed. I calculated it to be an impossible angle, but my teacher said it was 54°. Then he showed me his solution and I think it is totally bogus... He said it is the reaction of the road that gives the centripetal force, and then analysed the reaction being perpendicular to the road and with a y composant equal to the weight of the car and calculated the x component as being the required centripetal force. I disagree, as I am persuaded that the centripel force is given by the component of mg that is parrallel to the road, the reaction cancels the other component and thus the mass moves according to the parrallel component; this force is reponsable for the centripetal force. So if the angle is θ, mgsinθ = m(v^2/r) ;v = 60/3.6 r = 20 sinθ = 1.41723356 Which is impossible. I need an awnser since i have a test on monday.