Friction (Part 1) Bookmark this page Worksheets due Dec 15, 2022 10:00 PST Completed There are two kinds of friction, static friction and kinetic friction. Imagine pushing a heavy object like a refrigerator. Pushing force F V=0 y Friction Weight w Normal à F x 15 Fret - 0 If the refrigerator does not move, we have static friction which acts to keep objects in place: f. = Fpush The direction of the static friction force is parallel to the supporting surface opposite to the applied force. The object will not move as long as the applied force is not too large. The maximum force you can apply without setting the object in motion is given by the maximum static friction force f3, max = 14372 where Is is the coefficient of static friction, and n is the normal force. If your applied force is larger than the maximum static friction force (Fa > fs, mas) objects will start moving. The friction is now kinetic friction which applies to objects in motion (sliding objects), fk = Pin where (4% is the coefficient of kinetic friction. Notice that kinetic friction is a constant force. Its direction is parallel to the sliding surface (perpendicular to the normal force) and opposite the velocity. Pushing force F - y V=const. Friction Fx Weight w Normal F x Ener - 0