Why does mud fly off a rapidly turning automobile tire?
For mud to move in a circle, there must be a (net) force on it — directed toward the center of the circle. The value of that force is Fc = m v2/ r. As the velocity (or speed) increases, that force must increase if the piece of mud is to continue to move in a circle. As the velocity increases, the force that holds the mud to the wheel reaches its limit and the mud can no longer go around in a circle. When that limit is reached, the mud separates from the tire. Q6.5 Imagine that you attach a heavy object to one end of a spring and then whirl the spring and object in a horizontal circle (by holding the free end of the spring). Does the spring stretch? If so, why? Discuss this in terms of the force causing the circular motion. For the heavy object to move in a circle, there must be a (net) force on it, directed toward the center. That force is provided by the spring. For a spring to provide a force, it must be stretched. Q6.6 It has been suggested that rotating cylinders about 16 km in le
