Contact & Non-Contact Forces
Notice that some forces need contact between two objects (contact forces) while magnetic forces can act at a distance (non-contact forces)
What a learner can do afterwards
- Define contact forces as those needing objects to touch (e.g. push, pull, friction)
- Define non-contact forces as those acting at a distance (e.g. magnetism)
- Sort examples of forces into contact and non-contact categories
The lesson
Some forces need two things to touch before anything happens. When you push a door or pull a wagon, your hands are touching it the whole time. A force like this is called a contact force.
Think about kicking a ball. Your foot has to touch the ball before it can fly across the field. The touch is what makes the ball move, so kicking is a contact force.
Some forces can work without any touching at all. A magnet can pull certain metal objects toward it, even across a small gap. A force like this is called a non-contact force.
Hold a magnet near a paperclip on a table. Before your hand or the magnet ever touches the paperclip, it slides over and sticks to the magnet. The pull happened without any touching.
To sort a force, ask yourself one question: did the two things touch? If yes, it is a contact force. If they pulled or pushed without touching, it is a non-contact force.
Contact forces need touching, like a kick, while non-contact forces, like magnetism, can pull without ever touching.
Watch it
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.