1. You throw a stone off a cliff.
2. You hold a stone in your hand.
3. A train moves at a constant rate.
4. Your bicycle coasts, slows, and stops.
5. A car accelerates from 0 to 40 km/hour.
Name what kind of forces.
1) Unbal
2) Bal
3) Bal
4) Unbal
5) Unbal
...since F = ma anytime things are accel then it must be unbal