1. FORCE & MOTION

2. OBSERVATION

3. Observations · Pay close attention to the following. · Make notes on what you observe. · Do not take anything for granted.

8. Motion Observing a displacement of one thing relative to another. Describing Motion All motion is Relative The object moved in relation to the reference object or point.

9. Frame of Reference The context or limits of what we are discussing Helps us have a common scope for discussion

10. Measurement Defines a scaled common reference Can be replicated Is known and referenced Quantifies the change in position Common measurement scales are: Standard (English/US) Feet, Pounds, etc. Metric Meters, Grams, Liters Internationally accepted system (SI)

11. LINEAR MOTION Concepts: Scalars & Vectors

12. How Do We Describe “Where”? If objects move, how can we describe… – How far? – How much? – What direction? “How much” or “How far” is the magnitude of motion “What direction” is the direction of motion.

13. Two different “How Far’s” Distance – How far? – Scalar – Only measures path Displacement – How far from the start are we now? – What direction is it from the start to finish? – Vector – Measure distance and direction from start point to end point.

14. Scalars: Magnitude or Direction Magnitude How big How much What quantity OR Direction Cardinal Degree

15. Distance: A Scalar Distance Start Finish

16. Vectors: Magnitude & Direction Magnitude How big How much What quantity AND Direction Cardinal Degree

17. Displacement: A Vector Displacement Finish Start

18. Vector Addition “Connect the dots”

19. Vector Addition “Add” vectors to find the net result of the trip. Net Displacement: The sum of the vectors Start Finish Net Displacement Vector

20. Finding “Net Displacement” Using Math Add all Vertical vectors Add all horizontal vectors Us Pythagorean Theorem Start Finish Net Displacement Vector

21. Start Finish Net Displacement Vector

22. Sum of vertical vectors Sum of horizontal vectors Net Displacement a2a2 a b b2b2 c2c2

23. RATES Speed, Velocity, Acceleration

24. Vectors Are Found Throughout Physics There are three basic measureable properties in science – Mass – Distance – Time Physicists use these to describe the relationships and properties of an objects and their motions.

25. Speed Ratio of distance travelled to time taken Distance ÷ Time Scalar quantity No direction Path is important

26. Velocity Ratio of displacement to time taken Displacement ÷ Time Vector quantity Measured from start point to end point Disregards path

27. Comparing Speed and Velocity Dist. = 24 meters Time = 12 seconds Speed = 2 m/s

28. Comparing Speed and Velocity Disp. = 9 meters ENE Time = 3 seconds Velocity = 3 m/s ENE

29. Science Problems “What’s your problem with problems?”

30. Speedy Velocity Problems “How to work science problems” Jimmy the Frog hops around his pond. His hop-o-meter says he has travelled 36 meters. The sundial says it only took him 20 minutes. What was Jimmy’s speed?

31. How to work science problems Step 1: Identify your variables (with units!) Jimmy the Frog hops around his pond. His hop-o- meter says he has travelled 36 meters. The sundial says it only took him 20 minutes. What was Jimmy’s speed ? Distance: 36 meters Time: 20 minutes Speed: ???

32. Distance: 36 meters Time: 20 minutes Speed: ???

33. How to work science problems Step 2: Write down the equation

34. Distance: 36 meters Time: 20 minutes Speed: ???

35. How to work science problems Step 3: Change the equation to find the missing variable SpeedWhat do I need to find? No What does the equation solve for? Do I need to change the equation? Speed

36. Distance: 36 meters Time: 20 minutes Speed: ???

37. How to work science problems Step 4: Substitute variable values into formula. Distance: 36 meters Time: 20 minutes Speed: ???

38. Distance: 36 meters Time: 20 minutes Speed: ???

39. How to work science problems Step 5: Do (and show!!!) your work

40. Distance: 36 meters Time: 20 minutes Speed: ???

41. How to work science problems Step 6: Identify your answer Speed = 1.8 m/min.

42. Distance: 36 meters Time: 20 minutes Speed: ??? Speed = 1.8 m/min.

43. Distance: 36 meters Time: 20 minutes Speed: ??? Speed = 1.8 m/min.

44. ACCELERATION It’s all about change

45. Acceleration · Ratio of change in velocity to time · (Displacement ÷ Time) ÷ Time · Vector quantity · A change in velocity (direction or magnitude) constitutes acceleration

46. GRAPHING MOTION

47. Distance Distance/Time or Speed Graphs Speed 3.5 3 2.5 (m) 2 1.5 1 0.5 0 Object 1 1 2 3 4 Time (s)

48. Distance/Time or Speed Graphs Speed 3.5 3 2.5 2 1.5 1 0.5 0 Object 1 1 2 3 4 Time (s) Distance (m)

49. Distance/Time or Speed Graphs Speed 2.5 2 1.5 1 0.5 0 Object 1 1 2 3 4 Time (s) Distance (m)

50. Distance/Time or Speed Graphs Speed 12 10 8686 Object 1 420420 1 2 3 4 5 Time (s) Distance (m)

51. Displacement/Time or Velocity Graphs Velocity 3.5 3 2.5 2 1.5 1 0.5 0 Object 1 1 2 3 4 Time (s) Displacement (m)

52. Displacement/Time or Velocity Graphs Velocity 1.2 1 0.8 0.6 Object 1 0.4 0.2 0 1 2 3 4 Time (s) (m) Displacement

53. Displacement/Time or Velocity Graphs Velocity 3.5 3 2.5 2 1.5 1 0.5 0 Object 1 1 2 3 4 Time (s) (m) Displacement

54. Displacement/Time or Velocity Graphs Velocity 14 12 10 8 64206420 Object 1 1 2 3 4 5 6 Time (s) (m) Displacement

55. Velocity (m/s) Velocity/Time (Acceleration) Graphs Acceleration 3.5 3 2.5 2 1.5 1 0.5 0 Object 1 1 2 3 4 Time (s)

56. Velocity/Time (Acceleration) Graphs Acceleration 2.5 2 1.5 1 0.5 0 Object 1 1 2 3 4 Time (s) Velocity (m/s)

57. Momentum

58. Physical Properties of Objects Innate Properties Mass Speed Size Density Color Derived Properties Density Speed Weight

59. Observations on Objects in Motion Move in a straight line – Unless something pushes them off that line Speed wants to remains constant – Less friction is less loss of “speed” Massive objects are harder to move – Need more push to move

60. Observations on Objects in Motion If a moving object hits a non-moving object, the non-moving object is set in motion and the speed of the first moving object is reduced. How? Is there a relationship of properties that may explain this?

61. Observations on Objects in Motion What properties of objects seem to be involved? Speed Mass What should we call this Speed-Mass property? Momentum

62. Objects & Momentum

63. Newton’s Laws

64. Newton’s First Law An object will retain it motion unless an outside force acts upon it. Inertia: The resistance to movement of an object relative to its mass.

65. Newton’s Second Law An object will accelerate if an unbalanced force is applied to it.

66. Newton’s Third Law All forces between two objects exist in equal magnitude and opposite direction Weight of Object Normal Force of Object

67. END OF MOTION LECTURE