Unit 2 Force & Motion Ch 5 Sec 3 Friction
Friction friction - force that resists sliding between two touching surfaces slows down/stops moving objects w/o friction, a moving object would continue to move in a straight line at a constant speed
3 Types of Friction static friction sliding friction rolling friction prevents an object at rest from moving - caused by the attraction of atoms on touching surfaces - rougher, heavier objects have more static friction slows down a sliding object - caused by the microscopic roughness of surfaces makes a rolling object continue to roll
Air Resistance air resistance - a form of friction that slows down objects moving through air (lighter, broader objects have more air resistance)
Changing Friction Reducing Friction Increasing Friction Use lubricants Smoothing with Sand Paper Ball Bearings Sand on Ice Press Harder (more force)