Khan Academy
Khan Academy: Magnetic Force Between Two Currents Going in the Same Direction
Sal Khan shows how to determine the magnetic force between two currents going in the same direction. [10:59]
Khan Academy
Khan Academy: Inverse Square Law (Deflection Method)
An experiment to try to measure the change in the force of a magnet over a distance using the deflection of a compass. What is wrong with this approach?
Khan Academy
Khan Academy: Discovery of Magnetism: Compass Build (Stroke Direction)
An experiment that asks, does the direction that we stroke the needle determine the final orientation of a compass? [1:15]
Khan Academy
Khan Academy: Inverse Square Law (Method of Oscillation)
Here we compare the speed of compass oscillation vs. distance from a magnet. What kind of relationship do we observe? Is it linear? [2:08]
Khan Academy
Khan Academy: Are Two Magnets Stronger Than One?
A brief experiment that looks at whether the power of two magnets stuck together will increase the overall force.
Khan Academy
Khan Academy: Discovery of Magnetism: Compass Build (Magnet Orientation)
When making a compass, does it matter if we stroke the needle with the North vs. South pole of the magnet? Why? [1:07]
Khan Academy
Khan Academy: Discovery of Magnetic Fields: Magnetic Permeability
What happens to the magnetic field of a magnet in the presence of another material which is attracted to it? Why does this happen? [2:03]
Khan Academy
Khan Academy: Neutralize a Compass
This video demonstrates how to neutralize a compass using two needles. How could this help us later? Why does this work? [:46]
Khan Academy
Khan Academy: Discovery of Magnetism
Our ancestors noticed that certain rocks were attracted to each other. They also noticed that this force could be transferred onto certain metallic objects! This video is a quick demonstration of this discovery. [1:08]
Khan Academy
Khan Academy: Compass: Which Way Is North?
This video demonstrates the process of making a compass: How would you know which way is north if you had no reference? Can the direction of stroke alone tell you this? Are you sure? [1:00]
Khan Academy
Khan Academy: Compass Build (Stroke Direction)
This video demonstrates the process of making a compass: Does the direction in which we stroke the needle determine the final orientation? [1:13]
Khan Academy
Khan Academy: Compass Build (Magnet Orientation)
This video demonstrates making a compass: does it matter if we stroke the needle with the North vs. South pole of the magnet? Why? [1:06]