Directions :Complete the paragraphs by using the words listed below to fill in the blanks . 9.8 mlsz accelerate air resistance conservation of momentum continues decelerate equals fall freefall gravity laws of motion momentum satellites straight line terminal velocity velocity weightlessness Newton's 1. can be used to explain events in the natural world , such as how a pencil falls to the oor and how planets revolve around the Sun . In the absence of air, all objects fall at the same rate , because the force of Earth's gravity causes objects to 2. by 3. 4. can eventually counteract the acceleration from 5. . This is why a flat piece of paper falls slowly, but when the same paper is crumpled , it falls quickly . When the upward force of air resistance on an object 6. the downward force of gravity on the object , its '7. stops increasing . This is called the object's 8. 9. orbit Earth because of gravity. They travel very fast, but with each meter forward that they travel , they 10 . just a tiny bit due to Earth's gravity. Astronauts in Earth's orbit experience 11. because they are in 12. .W ithout gravity, satellites would con- tinue in a 13. away from Earth . Newton's laws also describe what happens in collisions . For example , in a moving car , a passenger is also in motion . When the car comes to a sudden stop , the passenger 14. in motion. To protect the passenger from striking the inside of the car, seatbelts and airbags 15. passengers slowly. Also, the 16. describes what happens in a collision . When two objects collide , the total 17. of the objects before the collision equals the total momentum of the objects after the collision