Vocabulary # 1 ( Newton's law of motion)

Definitions

1. force :a push or pull exerted by one object on another
2. friction: a force that opposes the motion of an object in contact with a surface
3. drag force: a force that opposes the motion of an object through a liquid or gas
4. gravity: a force of attraction that exist between all objects with mass
5. net force: the combined effect of all the forces acting together on an object
6. balanced forces: forces that cancel each other out when acting on a single object
7. unbalanced forces: forces that do not cancel each other when acting on a single object
8. inertia: the tendency of an object to oppose a change in motion
9. momentum: the mass of an object multiplied by its velocity

Sentences and illustrations

1. Pushing a door is a simple example of force.

2. Fiction opposes motion in contact with surfaces.

3. Drag force is similar to the force of sliding friction because both oppose motion.

4. Mass is what produces gravity and it is measured in kilograms.

5. Scientists believe that net force is equel to zero.

6. You can tell when forces are balanced because the motion of th object does not change.

7. When forces are unbalanced , it means the net force is not zero.

8. Passengers in car experience inertia as the car turns.

9. Momentum is simply mass times velocity.