. "Centripetal acceleration" . . . . "Bikes and cars" . . "This program considers the idea that circular motion must imply a force or component of a force toward the center of a circle, as in the Newtonian theory of how the Moon orbits the Earth. The reasons why bicyclists lean during turns, why roads are banked, and why car tires react as they do during a turn are investigated." . . . . . . . . . . . . .