Unit 8.4 Vocabulary

3. The force that attracts objects to the center of Earth or to the center of any object physical object with mass such as the Sun.
6. The forces caused by one surface or object rubbing against another as they move past each other.
10. Force An attractive force between two objects.
11. Friction forces that air particles apply against a moving object.
12. A very spread out collection of cloud, gas, and dust in outer space.
14. Small icy object orbiting the Sun that may have a long "tail" or halo when closer to the Sun.
15. Small piece of rock in the Solar System.

1. A system of Solar Systems, Stars, gas dust, and other matter.
2. The lack of any air particles in a volume.
4. A property of matter that causes objects to continue in a state of motion or rest unless changed by a force.
5. The motion pathway of a Solar System Object through space in a curved shape around another object.
7. The motion pathway determined by the forces of gravity of objects in space.
8. The size and distance of one object relative to another.
9. A pus or pull on an object.
13. Rocky bodies orbiting the Sun, mostly between Mars and Jupiter.