Understand how force, acceleration, gravity, friction, and wind resistance all relate to the exciting sport of alpine skiing. [4:00]

This lesson explains why static friction depends on normal forces. It is 1 of 2 in the series titled "Static Friction & Normal Forces."

The second part to a complicated problem. We figure out the tension in the wire connecting two masses. Then we figure our how much we need to accelerate a pie for it to safely reach a man's face. [9:28]

This lesson provides the learner with example problems involving tension forces. It is 1 of 2 in the series titled "Practice w/ Tension Forces."

This lesson provides the learner with example problems involving tension forces. It is 2 of 2 in the series titled "Practice w/ Tension Forces."

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

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."

This lesson introduces the concept of normal forces. It is 2 of 2 in the series titled "Normal Force."

This video covers the basics of gravity and the Law of Universal Gravitation. [15:42]

Moving on to the unit on the Physics of Electricity, it's time to talk about charge. What is charge? Are there positive and negative charges? What do those things mean? In this video episode, Shini talks about electrostatic forces,...

The video lesson is from Khan Academy's physics library. This lesson answers the question: What would happen to a slowly moving frozen sock on a frictionless planet.

Mr. Andersen shows you how to draw free body diagrams of various objects. The major forces (like gravity, normal, tension, friction, air resistance, etc.) are discussed and then applied to various problems.