# Newton's Laws of Motion Vocabulary

• 1. Displacement - the distance and direction between the starting and ending position

2 Speed - the distance traveled divided by the time needed to travel the distance

3. Velocity - the distance traveled divided by the time needed to travel the distance and the direction the object is moving in.

4. Acceleration - the change in velocity divided by the amount of time required for the change to take place; occurs when an object speeds up, slows down, or changes direction

5. Force - a push or pull

6. Contact force - a force that is exerted when two objects are touching each other

7. Long-range force - a force that acts from a distance even when the objects are not touching

8. First law of motion - states that an object at rest will remain at rest and an object in motion will remain in motion with the same speed and in the same direction unless acted on by an unbalanced force

9. Balanced forces - forces that are equal but in opposite directions and cancel each other out and no change occurs in the objects motion

10. Unbalanced forces - forces acting on an object that do not cancel each other and cause a change in the objects motion

11. Second law of motion - states that an object acted on by an unbalanced force will accelerate in the direction of the force with an acceleration equal to the force divided by the object's mass.

12. Gravitational force - force that every object exerts on every other object; depends on the masses of the objects and the distance between them.

13. Friction - a force between two surfaces in contact that resists the sliding of the surfaces past each other.

14. Third law of motion - states that forces act in equal but opposite pairs; for every action there is an equal and opposite reaction.