1. A soccer ball at rest starts rolling when kicked. Which type of force caused the motion?

2. Which of the following actions increases friction?

3. Two equal forces act in opposite directions on a box. What can you infer?

4. If you were asked to design a racing car, how could you reduce friction?

5. Force is any action that can change the state of motion of an object.

6. The electromagnetic force is weaker than the gravitational force.

7. Contact forces act without physical contact between objects.

8. Unbalanced forces cause a change in the motion of an object.

9. Friction always acts in the same direction as motion.

10. Static friction is usually greater than kinetic friction.