If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Discovery of Magnetism

7 videos
1 talkthrough
1 skill
The discovery of magnetism. What can we do with this invisible force?

Discovery of magnetism

VIDEO 1:09 minutes
Our ancestors noticed that certain rocks where attracted to each other. They also noticed that this force could be transferred onto certain metallic objects.

Compass challenge

PRACTICE PROBLEMS

Compass: Which way is north?

VIDEO 1:01 minutes
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?

Floating magnet

VIDEO 0:34 minutes
Can you use a magnet as a compass? How can you find North vs. South pole?

Compass build (stroke direction)

VIDEO 1:15 minutes
Does the direction which we stroke the needle determine the final orientation?

Compass build (magnet orientation)

VIDEO 1:07 minutes
Making a Compass: does it matter if we stroke the needle with the North vs. South pole of the magnet? Why?

Neutralize a compass

VIDEO 0:47 minutes
How to neutralize a compass using two needles. How could this help us later? Why does this work?

Compass interactions

VIDEO 0:45 minutes
If we float two identically magnetized needles they will always orient themselves in the same way. Why?