1. Warm-up What did you do over the weekend (no paper needed) Objective: The Learner Will calculate the displacement of an object traveling at a known velocity for a specific time interval “Those who mind don’t matter, those who matter don’t mind” Today Video Notes Hwk: Practice A

2. Chapter 2 Motion in One-Dimension

3. Video http://www.youtube.com/watch?v=JieOGvLgbfA

4. Some vocab Frame of reference – a system for specifying the precise location of objects in space and time Displacement – the change in position of an object Displacement = change in position = final position – initial position Displacement is not always equal to the distance traveled. Can be positive or negative Average velocity – the total displacement divided by the time interval during which the displacement occurred Average velocity = change in position / change in time = displacement/ time interval

5. Sample Problem A During a race on level ground, Andra runs with an average velocity of 6.02 m/a to the east. What is Andra’s displacement after 137 s? 5 step problem! Hwk: pg. 44 Practice A 1-6

6. Warm-up (No paper) What is the main unit used for… Time Distance/Displacement Velocity Objective: TLW calculate the displacement of an object traveling at a known velocity for a specific time interval “Those who mind don’t matter, those who matter don’t mind” Today Warm-up Check Homework Notes Finish outline and Section Review

7. Chapter 2 Motion in One-Dimension

8. Grade Practice A

9. Section 1

10. Questions Does the odometer in your car measure distance or displacement? Can you think of a circumstance in which it measures both distance and displacement?

11. Warm-up 9/25/13 An object goes from one point in space to another. After it arrives at its destination, its displacement is: a)Either greater than or equal to distance b)Always greater than distance c)Always equal to distance d)Either smaller than or equal to distance e)Always smaller than the distance it traveled OBJECTIVE: The learner will identify and describe velocity and speed. ‘You can throw in the towel, or you can use it to wipe off your sweat and keep pushing’ Which will you choose TODAY?

12. Average Velocity

13. Speed vs. Velocity Speed Always a positive number Describes how fast a particle is moving Velocity Positive or negative number Describes how fast the displacement is changing Both use SI unit of m/s

14. Instantaneous Velocity The average speed for a trip might be 53 miles/hour However, during this trip your instantaneous speed might have been 0 miles/hour at a stoplight……. Or 70 miles/hour on the open road

15. Instantaneous Velocity The velocity at a single instant in time If the velocity is uniform, or constant, the instantaneous velocity is the same as the average velocity If the velocity is not constant, than the instantaneous velocity, isn’t the same as average velocity And we must carefully distinguish between the two

16. Homework from yesterday Finish Section 1 Outline Section Review pg. 47 #1-4

17. Today Outline SECTION 2

18. Warm-up 9.26 What is the formula for velocity and what does it represent? If Joe travels 50 meters in 4 seconds what is velocity? If Danny runs at a rate of 4.9 meters per second and he runs for 25 seconds, how far has he traveled?

19. Acceleration Acceleration is the rate at which the velocity is changing We can change the state of motion of an object by changing its speed, its direction of motion, or both Units are in distance/time 2 – m/s 2 Acceleration = change of velocity / time interval

20. Example Problem Practice B pg. 49 A shuttle bus slows down with an average acceleration of -1.8m/s 2 How long does it take the bus to slow from 9.0m/s to a complete stop

21. HOMEWORK Practice B pg. 49 #1-5 Due Monday. We will check both Practice A and B at that time

22. Warm-up Spend a few minutes looking over formulas and their respective units. Don’t forget to add yesterdays formula to your notecard

23. Quiz

24. Warm-up What is the acceleration of football that is initially sitting still to 8 m/s in 2 seconds? (5-step) Have Section Review and Practice B out ready to grade. Today Warm-up/Objective Check Homework Practice C HWK: Practice C #1-4

25. Homework Check

26. Acceleration In physics the term acceleration applies to decreases as well as increases in VELOCITY The brakes of a car can produce large retarding accelerations, that is, they can produce a large decrease per second in the speed. This is often called deceleration. Accelerate in the direction of velocity-speed up Accelerate against velocity (decelerate)-slow down Accelerate at an angle to velocity-change direction

27. Find V with constant acceleration Another useful formula for finding velocity if acceleration is constant is V f =V i + a*Δt Units: v= m/s, t= sec, a=m/s 2

28. Find d with constant acceleration Another useful formula for finding distance if acceleration is constant is d=V i Δt +(1/2)aΔt 2 Units: v= m/s, t= sec, a=m/s 2

29. Practice C pg. 53 A racing car reaches a speed of 42 m/s. It then begins a uniform negative acceleration, using its parachute and braking system, and comes to rest 5.5 s later. Find the distance that the car travels during braking.

30. Warm-up Marissa’s car accelerates uniformly at a rate of +2.60 m/s 2. How long does it take for Marissa’s car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s? Objective: TLW calculate and describe final velocity after any displacement

31. Find V after any displacement

32. Acceleration In physics the term acceleration applies to decreases as well as increases in VELOCITY The brakes of a car can produce large retarding accelerations, that is, they can produce a large decrease per second in the speed. This is often called deceleration. Accelerate in the direction of velocity-speed up Accelerate against velocity (decelerate)-slow down Accelerate at an angle to velocity-change direction

33. Find V with constant acceleration Another useful formula for finding velocity if acceleration is constant is V f =V i + a*Δt Units: v= m/s, t= sec, a=m/s 2

34. Find d with constant acceleration Another useful formula for finding distance if acceleration is constant is d=V i Δt +(1/2)aΔt 2 Units: v= m/s, t= sec, a=m/s 2

35. Today Finish Practice C 3 & 4 pg. 53 Practice D #1-4 pg. 55 V f =V i + a*Δt d=V i Δt +(1/2)aΔt 2

36. Today! Check Practice C and D Sample Problem E Homework QUIZ ON FRIDAY! Objective: TLW identify and solve for velocity after any displacement

37. Homework Check Grade Practice C and D

38. Sample Problem E A person pushing a stroller starts from rest, uniformly accelerating at a rate of 0.500 m/s 2. What is the velocity of the stroller after it has traveled 4.75 m?

39. Tomorrow We will be doing a lab tomorrow. Make sure that you come to class prepared.

40. Free Fall Imagine there is no air resistance and that gravity is the only thing affecting a falling object. An object moving under the influence of the gravitational force only is said to be in free fall For free fall, it is customary to use the letter g to represent the acceleration is due to gravity The value of -9.8 m/s 2 should be used for the acceleration during free fall due to gravity The negative sign in front of gravity indicates the direction gravity is acting -DOWN

41. Rising Objects Now consider an object thrown straight up: It moves upward for a while At the highest point, when the object is changing its direction from upward to downward, its instantaneous speed is zero It then falls downward as if it had been dropped from rest at that height During the upward part of this motion, the object slows from its initial upward velocity to zero velocity The object is accelerating because its velocity is changing (due to the downward pull of gravity) How much does its speed decrease each second?

42. Free fall Gravity is always acting down, or in a negative direction Gravity causes the ball to slow on the way up, and speed up on the way down Velocity is POSITIVE on the way up and NEGATIVE on the way down At the very top of the balls flight, velocity is ZERO for just a moment

43. Symmetry in Free Fall When something is thrown straight upward under the influence of gravity, and then returns to the thrower, this is very symmetric The object spends half its time traveling up; half traveling down Velocity when it returns to the is the opposite of the velocity it was thrown upward with Acceleration is 9.81 m/s 2 and directed DOWN the entire time the object is in the air!

45. Warm-up Be attentive in your seat when the bell rings No calculators needed today.

46. Lab today Computer lab

47. Warm-up Copy the graph below and then draw in what it would look like for a person to walk at a steady pace for 5 seconds to 5 meters. Then show what it would look like for the man to walk to -10 m at a fast steady ready.

48. Moving Man What does a graph of a person standing still look like? What does a graph of a person moving away from an observer look like? What does a graph of a person moving towards an observer look like? How do differences in speed appear on the graph?

49. Classwork Section Review pg. 59 Reviews uniform acceleration and velocity vs time graph

50. Warm-up What is the definition of acceleration? On the graph below if the Y-axis was velocity instead of displacement what would constant positive acceleration look like? What about an object undergoing constant positive acceleration with positive velocity?

51. Homework Check

52. Quiz

53. Warm-up What are the units for the following Displacement in the y-direction Velocity Acceleration Time Displacement in the x-direction Objective: TLW relate the motion of a freely falling body to motion with constant acceleration, calculate displacement, velocity, and time at various points in the motion of a freely falling object. “Just keep going. Everybody gets better if they keep at it.” – Ted Williams

54. Free Fall Imagine there is no air resistance and that gravity is the only thing affecting a falling object. An object moving under the influence of the gravitational force only is said to be in free fall For free fall, it is customary to use the letter g to represent the acceleration is due to gravity The value of -9.8 m/s 2 should be used for the acceleration during free fall due to gravity The negative sign in front of gravity indicates the direction gravity is acting -DOWN

55. Sample Problem Fpg.63 Jason hits a volleyball so that it moves with an initial velocity of 6.0 m/s straight upward. If the volleyball starts from 2.0m above the floor, how long will it be in the air before it strikes the ground?

56. Warm-up Get out your homework from yesterday

57. Homework Check Only grade #’s 1 and 2

58. Practice Test Treat this as a real test. We will come into class tomorrow and grade it. If you finish early go through your book and look for definitions and make sure that you know them

59. Warm-up 1) What is the correct description of any change of position farther to the right of zero? 2) A dog walks from +4 m to +2 m. Which of the following statements is true about the dog’s motion?

60. Practice Test Make corrections together as a class. Use a red pen to show some ideas that you need to focus on. When finished you are to work on practice test question in the book.