Motion and Speed

1. Motion and Speed

2. On the front: • Physics • On the back: • The branch of science that deals with matter, energy, space, time, and the relationship between them. Flash Card

3. Teach the Teacher: Who do you miss the most and why? • Review: What 4 things does physics cover? Warm-up 1/22/13

4. http://www.nsf.gov/news/special_reports/olympics/bobsled.jsp Physics Matter!

5. On the front write: • Motion • On the back write: • a change of position of an object. Flash Card

6. Motion occurs when an object changes position. • You don’t need to see something move to know that motion has taken place. • You just need a reference point to know if motion occurred Sec. 1 Describing Motion

7. Distance—how far an object moved • The SI unit for distance is the meter, m • Displacement—the distance and direction of an object’s change in position from the starting point. Distance and Displacement

9. Rate—any change over time • Speed—the distance an object travels per unit of time. What is Speed? fastest

10. D S T divide multiply • The speed of an object can be calculated from this equation: • Speed = Distance Time • S=D/T • When working equations • Write the formula • Plug in the values for each known • Calculate the answer • Write the answer and a unit Calculating Speed

11. On a distance vs. time graph, time goes on the x-axis and distance goes on the y-axis. • The slope (steepness) of the line represents the speed of the object. Graphing Motion Distance  Speed Time↑

12. Y-axis faster slower Distance (meters) Draw this on your paper! Standing still X-axis Time (seconds)

13. Teach the Teacher: If your life song or theme song, what song would it be (that I want to know about)? • Review: Tell me anything you can about motion. Warm-up 1/23/2013

14. On the front write: • Reference Point • On the back write: • Determines an object’s position and if motion happened Flash Card

16. Which one is the fastest? • Which one isn’t moving?

17. Distance Time Graphs • What information is recorded on the x-axis? • In what units is distance measured on the graph? • The graphs represent three swimmers, What does the slope of the lines tell you about the swimmers?

18. Which swimmer swam the fastest? • Which swimmer stopped for 10 minutes? • How far did the blue swimmer travel in 15 minutes?

19. Cheetah 70 • Pronghorn antelope 61 • Lion 50 • Thomson's gazelle 50 • Wildebeest 50 • Springbok 50 • Quarter horse 47.5 • Cape hunting dog 45 • Elk 45 • Snail 0 What are the fastest animals (mph)?

20. The Band is on the Field! The real world graphing…

21. Average speed—the total distance traveled divided by the total time of travel. • Used when speed is changing • Instantaneous speed—the speed at a given point in time. • Ex. Speedometer Average & Instantaneous Speed

22. Physics To Win It! Your Chance to Win…. AND LEARN PHYSICS Modeled off of Minute to Win It

23. Use the CBR to make a distance vs. time graph, the person who matches the graph exactly, within 5 tries, and answers these questions correctly gets a signature/stamp (THIS IS NOT TIMED) (I MUST SEE EVERYONES GRAPH) • Draw the Graph you matched perfectly..w/ labels • 1. What information is on the x-axis? What information is on the Y-axis • 2. What did you do when the line was flat (or horizontal)? • 3. Should you walk forward or backward for a segment that slopes up? Physics To Win It Challenge (PTW): Match the Graph

24. 200 samples per second with a range between 0.5 meters and 6 meters • (1.5 feet and 18 feet) • better results with a relatively hard, smooth surface (aim for gold sheet) • You break you buy (cords are delicate!) Calculator-Based Ranger

26. Speed describes only how fast something is moving. • Velocity—includes the speed of an object AND the direction of its motion Velocity

27. Velocity can change in 2 ways • Change in speed • Change in direction Or Both • Ex: a race car has a constant speed of 100km/hr around an oval track. • Speed is constant, but velocity changes Change in Velocity

28. On the front write: • Average Speed • On the back write: • the total distance traveled divided by the total time of travel Flash Card

29. On the front write: • Instantaneous Speed • On the back write: • the speed at a given point in time Flash Card

30. Acceleration—the rate of change of velocity. • The change in velocity over time • acceleration = change in velocity time • When something speeds up, it has a positive acceleration • When something slows down, it has a negative acceleration. Acceleration

31. Change in velocity= vfinal–Vstart • Acceleration= vfinal–Vstart • Time • Units= distance (meters, miles)/sec2 Breaking Acceleration Apart

32. Acceleration Triangle

33. Changing Direction • Remember: • A change in velocity can be either a change in speed or a change in direction. • Any time an object changes direction, its velocity changes and it is accelerating.

34. Negative vs. Positive Acceleration • An object speeds up if its acceleration is in the direction of its motion. • An object slows down if its acceleration is opposite to the direction of its motion.

35. Velocity vs Time Graph of Positive Acceleration

36. On the front write: • Slope of graph • On the back write: • D vs T graph=speed • V vs T graph=acceleration • Steeper slope=more speed or acceleration Flash Card

37. Velocity vs Time Graph of Negative Acceleration

38. Zero Acceleration • When an object has a constant velocity, it has 0 acceleration.

39. An Object Changing Acceleration

40. How Stuff Works: Roller Coaster & The Human Body

41. See acceleration happening

42. On the front write: • Acceleration • On the back write: • The change in velocity over time (draw triangle) Flash Card

43. On the front write: • Velocity • On the back write: • The speed and direction of an object Flash Card