1. 10/28 (p 42 ) Motion Notes- Speed

4. An object is in motion if it changes position relative to a reference point. Objects that we call stationary—such as a tree, a sign, or a building—make good reference points. The passenger can use a tree as a reference point to decide if the train is moving. A tree makes a good reference point because it is stationary from the passenger’s point of view.

5. Reference Point: A place or object used to compare and determine if an object is in motion. Should not be moving, should be visible to compare. http://rpdp.net/terms/mid/full/m/motion.htm http://rpdp.net/terms/mid/full/m/motion.htm

6. Describing Motion Whether or not an object is in motion depends on the reference point you choose.

8. Earth rotates on its axis at 1,100 mph or 1670 km/hr. Earth orbits the Sun at 68,000 mph or 107,000 km/hr

9. The whole galaxy rotates at 490,000 mph

10. Distance When an object moves, it goes from point A to point B – that is the DISTANCE it traveled. (SI unit is the meter) Distance is how far an object has moved during its motion. A B

11. Measuring Distance Meter – international unit for measuring distance. = 50 m 1 mm

12. Displacement Displacement is how far out of place the object is; it is the object’s overall change in position, directly from the starting to the ending point. In this example, the displacement is 5 km northeast whereas the distance is 1+1+2+3= 7km

14. Calculating Speed Speed (S) = distance traveled (d) / the amount of time it took (t). Copy on left page: S (speed, how fast, rate)= d/t SI unit m/s D (distance, how far)= s x t SI unit m T (time, how long) = d/s SI unit s D ST

15. Calculating speed If I travel 100 kilometer in one hour then I have a speed of… 100 km/h If I travel 1 meter in 1 second then I have a speed of…. 1 m/s If I travel 100 km in 2 hours, I have a speed of 100 km/2 h= ____ S = d/t

16. Speed = distance time A snail crawls 1 m in 100 seconds. What is the speed of the snail? = 1 m Problem 1 (left hand side p.): Create a problem like the one above and solve to find the speed. Please use different numbers! =.01 m/s 100s

17. Problem 2 =I ran for 2 hours at a speed of 6 km/h. How far did I run? Far means distance, time or speed?

18. Types of Speed Constant speed = unchanging speed over a certain period of time. Speed is usually NOT CONSTANT –Ex. Cars stop and go regularly –Runners go slower uphill than downhill Average speed = total distance traveled/total time. Instantaneous speed= speed at any given time.

19. Instantaneous Speed Speed = Distance/timeAverage speed = Total distance/Total time What is instantaneous speed? Instantaneous speed is the speed of an object at a certain time.

20. Problem 3: Tina ran 1000 m in 3 minutes. Then ran another 1000 m uphill in 7 minutes. a.Did she have a constant speed? b. Find her average speed. A) 100 m/min B) 2000 m/min C) 10 m/min D) 200 m/min E) 20 m/min

21. Total Dist. = 1000 m + 1000 m = 2000 m Total Time = 3 min + 7 min = 10 min Ave speed = total dist/total time = 2000m/10 min = 200 m/min

22. Problem 4 Jane ran 10 km in 2 hours, and the next 5 km in 1 hour. Did she have a constant speed? (Find speed for each part of her run, is it the same?). What is her average speed? (Total d/total t)

23. What would be the best reference point to tell if the canoe is moving or not? a.The water b.The sky c.The shore d.The lighthouse e.The island

25. An object is in motion if it changes position relative to a __________ point. Objects that we call stationary—such as a _____, a sign, or a building—make good reference points. The passenger can use a tree as a reference point to decide if the train is moving. A tree makes a good reference point because it is stationary from the passenger’s point of view.

26. Reference Point: A _________ or __________used to compare and determine if an object is in motion. Should _______be ___________, should be ________ to compare.

27. Distance When an object _______, it goes from point A to point B – that is the DISTANCE it traveled. (SI unit is the _________ ) Distance is how _____ an object has moved during its motion. A B

28. Displacement Displacement is how far out of place the object is; it is the object’s ______ change in position, directly from the _______ to the ending point. In this example, the displacement is 5 km northeast, whereas the distance is 1+1+2+3= 7km

30. Calculating Speed Speed (S) = distance traveled (d) / the amount of time it took (t). S (speed, how fast, rate)= d/t SI unit m/s D (distance, how far)= s x t SI unit m T (time, how long) = d/s SI unit s D ST

31. Calculating speed If I travel 100 kilometer in one hour then I have a speed of… 100 km/h If I travel 1 meter in 1 second then I have a speed of…. 1 m/s If I travel 100 km in 2 hours, I have a speed of 100 km/2 h= ____ S = d/t

32. Speed = distance time A snail crawls 1 m in 100 seconds. What is the speed of the snail? = 1 m Problem 1 (left hand side p.): Create a problem like the one above and solve to find the speed. Please use different numbers! =.01 m/s 100s

33. Solve on left hand side page: Problem 2 =I ran for 2 hours at a speed of 6 km/h. How far did I run? Far means…. distance, time or speed?

34. Types of Speed Constant speed = ________ speed over a certain period of time. Speed is usually ______ CONSTANT –Ex. Cars stop and go regularly –Runners go slower uphill than downhill Average speed = _______ distance traveled/total ________. Instantaneous speed= speed at ______ given ________.

35. Instantaneous Speed Speed = Distance/timeAverage speed = Total distance/Total time Instantaneous speed is the speed of an object at a certain time.

36. Problem 3: Tina ran 1000 m in 3 minutes. Then ran another 1000 m uphill in 7 minutes. a.Did she have a constant speed? b. Find her average speed. A) 100 m/min B) 2000 m/min C) 10 m/min D) 200 m/min

37. Problem 4 Solve on left hand side page: Jane ran 10 km in 2 hours, and the next 5 km in 1 hour. Did she have a constant speed? (Find speed for each part of her run, is it the same?). What is her average speed? (Total d/total t)

38. OQ: How long would it take a car driving at 100 km/h to go 600 km?

39. 11/6 Motion Notes: Velocity IQ: Did the football in the cartoon move? Did the kid move? How can you tell?

41. It has both speed and direction. Ex. 50km/h south, 10m/s NE

42. Do all these planes have the same speed? Is their velocity different?

43. Because velocity depends on direction as well as speed, the velocity of an object can change even if the speed of the object remains constant. Velocity Describing Motion The speed of this car might be constant, but its velocity is not constant because the direction of motion is always changing.

44. Velocity Velocity is a description of an object’s speed and direction. As the sailboat’s direction changes, its velocity also changes, even if its speed stays the same. If the sailboat slows down at the same time that it changes direction, how will its velocity be changed?

45. Speed vs. Velocity Usain Bolt

47. It has both ______ and ___________. Ex. 50km/h ______, ________ NE

48. Because velocity depends on direction as well as speed, the velocity of an object can change even if the speed of the object remains constant. Velocity Describing Motion The speed of this car might be constant, but its _________ is not constant because the __________ of motion is always __________.

49. Velocity Velocity is a description of an object’s speed and direction. As the sailboat’s direction changes, its velocity also changes, even if its speed stays the same. If the sailboat slows down at the same time that it changes direction, how will its velocity be changed?

50. Problem : Rocket 1 goes 2000 km in 2 hrs. towards the East. Rocket 2 goes 3600 km in 3 hrs. towards the East. Do they have the same a.Speed? b. Velocity? Explain.

51. Which of the following could be the velocity of a moving object? A.12 m/s B.100 m NE C.0.5 m/s W D.1300 s N

52. 11/7 Speed Challenge lab IQ: Word bank: Constant speed, velocity, average speed, instantaneous speed a.I hiked up the mountain at a speed of 1 m/s- _____________ b.At t=10s the rocket was going1000 m/s- ________________ c.The plane flew at 700 km/h E-__________ d.The earth rotates at 1100 mph.- ___________.

53. 11/05 p. 46 Motion Notes: Acceleration IQ: Describe the motion of each car: Car (a) is going at ________________ Car (b) is ________________ Car (c) is ________________

54. Speed and velocity review (HW) Fill in the blanks for Velocity notes. Answer the problem on slide 4.

55. Instantaneous vs. Average speed or velocityInstantaneous vs. Average speed or velocity

56. Acceleration Acceleration is a change in speed or direction of an object. Accel = final vel.-initial vel. m/s 2 Time m/s 2

57. Calculating Acceleration If an object is moving in a straight line  Units of acceleration: m/s 2 or m/s/s

58. Calculating Acceleration 0 s 1 s2 s3 s4 s 0 m/s 4 m/s 8 m/s 12 m/s16 m/s

59. A cheetah goes from 0 to 60 mi/h in 3s. What is its acceleration?

60. A baseball going at 60 km/h reaches the catcher’s glove in 4 seconds. What is its average acceleration?

61. As a roller-coaster car starts down a slope, its speed is 4 m/s. But 3 seconds later, at the bottom, its speed is 22 m/s. What is its average acceleration? Calculating Acceleration What information have you been given? Initial speed = 4 m/s Final Speed = 22 m/s Time = 3 s

62. Types of acceleration Increasing speed, positive accel. –Example: Car speeds up at green light Decreasing speed, negative accel./deceleration –Example: Car slows down and comes to a stop at red light, an arrow or a bullet after being shot. (Add to your notes) Changing Direction –Example: Car takes turn (can be at constant speed) screeeeech

63. Centripetal acceleration

64. Is the car below accelerating?

65. Physics of NFL

66. A car that starts from rest and speeds up to 30 km/hr in 10 seconds has positive acceleration. Acc= A car that slows down, and comes to a stop from going 100 km/hr in 5 secs. has a negative acceleration or deceleration. Acc=

67. Question How can a car be accelerating if its speed is a constant 65 km/h? If it is changing directions it is accelerating

68. Acceleration while skydiving Complete yellow Motion map. Tape on p. 46.

69. What happens to the motion of a baseball after it is hit by the batter and flies towards the outfield? It a.Goes at a constant speed b.Accelerates c.Decelerates d.Has a speed of zero.

70. Acceleration Acceleration is a __________ in ________ or ___________ of an object. Accel = final vel.-initial vel. m/s 2 Time m/s 2

71. Calculating Acceleration If an object is moving in a straight line  Units of acceleration: m/s 2 or m/s/s

72. Calculating Acceleration 0 s 1 s2 s3 s4 s 0 m/s 4 m/s 8 m/s 12 m/s16 m/s

73. As a roller-coaster car starts down a slope, its speed is 4 m/s. But 3 seconds later, at the bottom, its speed is 22 m/s. What is its average acceleration? Calculating Acceleration What information have you been given? Initial speed = 4 m/s Final Speed = 22 m/s Time = 3 s Acc=

74. Types of acceleration _________ speed, _________ accel. –Example: Car speeds up at green light ____________ speed, negative accel./_____________ –Example: Car slows down and comes to a stop at ________ light Changing ____________ –Example: Car takes ______ (can be at constant speed) screeeeech

75. Centripetal acceleration

76. Is the car below accelerating?

77. Solve for Acceleration. A car that starts from rest and speeds up to 30 km/hr in 10 seconds has __________ acceleration= A car that slows down, and comes to a stop from going 100 km/hr in 5 secs. has a ____________ acceleration or deceleration=

78. Question How can a car be accelerating if its speed is a constant 65 km/h?

79. OQ: Which of the following is NOT accelerating? a.The earth b.A skier going downhill c.A car sitting in the driveway d.A school bus stopping.

80. Centripetal Acceleration When you move in a circular motion, you have continuous acceleration (always changing direction) Acceleration from spinning Centripetal means “toward the center”

81. OQ: Draw the v/t graph for an object that starts out at a high velocity, slows down constantly and comes to a stop.