Newton s Second Law of Motion Force and Acceleration

Transcription

1 Chapter 3 Reading Guide: Newton s Second Law of Motion Force and Acceleration Complete the Explore! Activity (p.37) 1. Compare the rate at which the book and paper fell when they were side-by-side: Name: Date: Period: 2. Compare the rate at which the book and paper fell with the paper on top of the book: 3. What effect does air resistance have on a falling object? 3.1) Developed the Concept of (p 38) 1. Explain what this diagram shows about acceleration (see right): 2. Write the formula for acceleration Acceleration = Change in velocity Time interval 3. List three ways that velocity can change: What does the Greek letter delta ( ) mean: 5. Explain what it means to have an acceleration of 5 km/hr/s: 6. Why are there two units of time in an acceleration unit? 7. Define Free Fall: 8. What is very significant about the number 10 m/s/s (same as 10 m/s 2 )? 9. See the picture at right. Sketch in the missing speedometer needle at t=3 s, 4 s, and 5 s. Then explain what the picture shows.

2 10. Describe the acceleration experienced by a ball thrown upwards from the moment it leaves the throwers hand to the moment it impacts the ground. (A sketch can help): 3.2) Causes Acceleration (p 40) 1. Acceleration is caused by. For example: 2. Draw a diagram to explain the Net Force on a box if you push on it with a 25 N force and someone else pushes on it in the opposite direction with a 15 N force. 3. What does it mean to say that the acceleration of an object is proportional to the net force acting on the object? 4. What does the symbol ( ) mean in the expression Acceleration net force? 5. Explain what the diagram at right is showing: 6. Complete the Concept Check questions on p 40. (attach your own paper) 3.3) MASS is a Measure of INERTIA 1. A more can has more than an can. In other words it is more to a in. 2. Why do tractor trailer trucks require powerful engines? 3. Explain the difference between mass and volume.

3 4. What is the main difference between mass and weight? 5. How can inertia help you sense an object s mass? 6. Define: Mass: Weight: 7. What does it mean to say that Mass Weight? 8. Complete the Concept Check questions on p 42. (on your own attached paper). 9. The standard unit for mass is: 10. On Earth; 1 kg = N, 1 kg = pounds. 11. What happens to the weight of a 1 kg mass as it is moved away from the earth where gravity is less? 3.4) Mass Resists Acceleration (p 43) 12. Explain what this picture shows about the relationship between mass and acceleration? 13. Now explain what it means to say, Acceleration is inversely proportional to mass. 14. More mass means acceleration because more mass means more (also known as I.) 15. Complete the Concept Check questions on p 44. (on your own attached paper). 3.5) Newton s Second Law Links Force, Acceleration and Mass (p 44) 16. Write Newton s Second Law (in words) in the box below: Newton s Second Law

4 17. Write the second law as an equation in the box below: Newton s Second Law Acceleration units must be: Acceleration = Force units must be: Mass units must be: 18. A. If the engine in a 4000 kg truck exerts a 6,000 N force, what is the acceleration of the truck? (show all work) b. If we double the engine force to 12,000 N, what will be the acceleration of the truck? c. If we load the truck so that it now has a mass of 8000 kg, what will be the acceleration of the truck (with the original 6000 N force)? 19. If the net force on an object is doubles, its acceleration will. If the mass of an object is doubled, the acceleration will be. 20. What will happen to the acceleration if we double both the mass and the net force acting on an object? Explain. 21. Complete the Concept Check questions on p 45. (on your own attached paper). 22. Calculate the acceleration on each of the objects shown here. Show your work completely: A. B. C. D.

5 3.6) Friction is a Force that Affects Motion (p 45) 23. Friction always acts in a direction. 24. Study the Practicing Physical Science on page 46. Then complete the worksheet on the last page in this packet. 3.7) Objects in Free Fall have Equal Acceleration (p 47) 25. Free Fall means falling under the influence of. 26. What did Galileo demonstrate at the Leaning Tower of Pisa? 3.8) Newton s Second Law Explains Why Objects in free Fall have Equal Acceleration 27. Show in a labeled sketch and with equations how Newton s Second Law explains why the acceleration of all falling objects is the same (on earth). 3.9) Acceleration of Fall is Less When Air Drag Acts 28. Use the terms terminal speed and frontal surface to explain how a flying squirrel manages to land safely jumping from a high tree.

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