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Monday 10/29/2012. Describe how you studied for the test?. 1. What is the book definition for motion?. Motion is a change in position over time. 2. Describe a “frame of reference” or a reference point. A frame of reference is a group of objects from which you measure your position or motion.
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Monday 10/29/2012 Describe how you studied for the test?
1. What is the book definition for motion? • Motion is a change in position over time.
2. Describe a “frame of reference” or a reference point. • A frame of reference is a group of objects from which you measure your position or motion.
3. Speed is • Distance/time • The total distance that you have traveled divided by the total time it took to travel.
4. Velocity is • Velocity is the measurement that combines both speed and direction. • 30 mph south (example)
5. How does friction affect you in your daily life? • Friction helps you walk. • Friction keeps the tires on a car rolling. • Friction helps you hold a pencil.
6. What is friction? • Friction is a force that opposes motion of one object passing another. • Rubbing your hands together..
7. What happens when you accelerate? • You are either speeding up, slowing down or changing direction.
9. What is air resistance? How does air resistance affect an airplane? • When an object moves through the air, the air hits the object and the object slows down. • Airplane: gravity is trying to pull it down. The plane is getting hit with pockets of air, each pocket tries to slow it down. Page 585 • Where does air resistance slow down an airplane?
10. How can we tell when the forces on the object are balanced? • Balanced forces often point in the opposite direction and equal zero. • Example: 23 N 23 N • If we go 23 to the right and then 23 to the left we end up at zero on a number line.
11. A force that causes motion is known as a _____ force. • Unbalanced • WHY?
12. How does the massof an object affect its motion? Use an example in your answer. • If I am in a “bug” driving down the road and my friend is in a semi-truck and we are both moving with the same amount of force. “BOOM” we hit a brick wall. • What happens due to the mass of the semi being larger?
14. If I throw a baseball with a small amount of force and I throw a baseball with a large amount of force. How will the motion of the baseball be changed? • The baseball thrown with more force will go farther than the one with the smaller force.
15. If I am pushing a shopping cart that is half full and then I push a shopping cart that is full. How does the mass of each affect the force I need to use to keep the carts in motion on a flat surface? • I would have to apply a larger force to the shopping cart that is full.