Kennedy and Lilly are in science class. They are asked to prove that some forces are non-contact
forces. The girls list five examples of objects exerting a force on each other without touching. Do you
agree with their list? Tell why or why not?
1. Two like magnetic poles repel each other.
2. Putting on a wool sweater can make your hair get static electricity when it rubs against the
sweater.
3. When you bring two negatively charged balloons near each other they push each other away.
4. Magnets stick to a refrigerator.
Number 1 and 3 demonstrate non-contact forces because the magnets or electrically charged objects exert
forces on each other without touching.
3 is the only example of non-contact forces since like charges repel each other.
Number 1 and 4 are non-contact forces since they both use magnets.
All four are good examples of non-contact forces since they all use either magnets or electric charge which are
non-contact forces.