This lesson provides the learner with the coefficients of kinetic friction for some common surfaces. It is 1 of 2 in the series titled "Common Coefficients of Kinetic Friction."

This lesson provides the learner with the coefficients of static friction for some common surfaces. It is 1 of 2 in the series titled "Common Coefficients of Static Friction."

This lesson explains how friction is part of the net force acting on an object. It is 1 of 2 in the series titled "Friction & Net Force."

Robert Carpick, a curler and a friction scientist, explains what scientists now think causes ice to be slippery. It is believed that there is a nano-thin layer of water on top of the ice that allows skates to slide along ice. Aired Feb....

A video illustrates what friction is. Investigate whether friction can occur in different states of matter. [2:22]

Corrects an numerical error in a previous video on how a block of wood is kept stationary by the force of friction.

Learn about this simple machine, and see how it reduces the effort required to move certain objects through this fun and animated learning module.

Why is it hard to move a heavy bookcase across a carpeted floor? And why is it easier to keep it moving than it was to get it started moving? You might think it's all about weight, but actually it's about friction. Two kinds of friction!...