LET’S TRY ONE
A cart has a 7 N force right and a 3 N force left. What is the net force?
4 N right
The opposite forces subtract: 7 − 3 = 4 N toward the larger rightward force.
Learning steps & teaching tips
Calculate a net force from stated opposite directions and distinguish balance from rest.
- Choose one positive direction.
- Combine the signed force values in newtons.
- Describe a change in motion from net force, rather than guessing an object's present speed.
Try it together
Draw arrow cards with force values. Combine them along one line and write what is known—and unknown—about the object's motion.
Add forces in the same direction and subtract opposite forces; zero net force does not by itself mean zero speed.