1. What is the minimum coefficient of static friction required for a roller-coaster car to complete a circular loop of radius r, if it is traveling with sufficient speed v? I'm just very confused with all of this because the question seems so broad and there are so many things to consider. A little bump or nudge in the right direction is highly appreciated. Also I don't really know what kind of things I am supposed to assume besides the weight of the rollercoaster car, the velocity, and the radius. Is that sufficient information? Help is highly appreciated!