2. Warm Up (Page 21) 1. If Olivia drives at 68 mph for 5 hours, how far did travel? 1. Mrs. Ward is taking a trip to Washington state over the summer break. If she travels at 70 mph for 24 hours, would she make it to WA? Why or why not? (p.s. How far do you think Washington is? Think critically!!!)

3. Announcements/Agenda We need to review and complete our stations from yesterday. Velocity and Acceleration Notes and Practice today

4. Speed it up!

5. Velocity: What is it? Velocity is a speed in a specific direction. Formula: v= d/t + direction Examples of velocities: 30 m/s to the left 45 mi/hr west 18 km/s up

6. Velocity Example Problems Mejde was taking a rocket ship to his home in outerspace. If the rocket travels 900 km in 2 minutes towards the sun, what is his velocity? Ms. Britain is driving North to her parents’ home in New Hampshire. If she drives 720 miles for 12 hours, what is her velocity?

7. REMEMBER!!!!!!! Solve Velocity problems JUST LIKE SPEED problems. Just add in a DIRECTION.

8. Speed and Velocity…. http://www.youtube.com/watch?v=DRb5PSxJerM

9. Acceleration Acceleration is a change in velocity over time

10. What two components make up velocity?

11. Velocity Speed Direction

12. Acceleration Def.: Change in _________ over ___________ Can be change in speed or direction (speed up, slow down, or change direction)

13. Acceleration Def.: Change in _velocity_ over __time____ Can be change in speed or direction (speed up, slow down, or change direction)

14. Is this ball accelerating? Yes! Because the direction is changing.

15. Which cars are accelerating? Cars B and C! A B C

16. Acceleration is not just a change in velocity, it’s how fast that change happens.

17. Which car has the greatest acceleration? Car C! A B C

18. Discovery Education Video http://player.discoveryeducation.com/index.cfm?guid AssetId=A04DA40D-810B-4057-B333- 7752AF27FAA2&blnFromSearch=1&productcode=US http://player.discoveryeducation.com/index.cfm?guid AssetId=A04DA40D-810B-4057-B333- 7752AF27FAA2&blnFromSearch=1&productcode=US

19. To measure it, you must know the initial velocity, the final velocity, and the time it takes to make the change.

20. Acceleration Def.: Change in velocity Can be change in speed or direction (speed up, slow down, or change direction) Acceleration = ∆v/ t

21. Acceleration Initial Velocity –Object’s velocity when you start measuring acceleration. Final Velocity –Object’s velocity when you finish measuring acceleration.  - Greek letter delta – “change”

22. Acceleration = change in velocity time a=  v t The unit for acceleration is m/s 2.

23.  v is the difference between the final velocity (v f ) and the initial velocity (v i ).  v = v f - v i

24. Acceleration Def.: Change in velocity Can be change in speed or direction (speed up, slow down, or change direction) Acceleration = ∆v/ t ∆v = v f – v i

25. Example 1 A roller coaster’s velocity at the top of a hill is 10m/s. Two seconds later it reaches the bottom of the hill with a velocity of 26m/s. What is the acceleration of the roller coaster?

26. Answer v f = 26 m/s v i = 10 m/s t = 2 s Acceleration = ∆v/ t a = 26m/s – 10m/s 2 s a = 16m/s 2s a = 8m/s/s or 8m/s 2

27. Examples 2-4 – Try them! 2. A car travels at 60 miles per hour around a curve. Is the car accelerating? 3. A car travels in a straight line at 60 mi/hr. Is the car accelerating? 4. A car goes from 0 mph to 60 mph in 6 seconds. What’s the car’s acceleration?

28. Answers: 1. Yes! Because it’s changing direction. 2. No! It’s not changing speed or direction. 3. -vf = 60 mph vi = 0 mph t = 6 s -a = vf – vi t -a = 60 – 0 mph = 10 m/s 2 6 s

29. Graphing Velocity vs. Time Constant acc.No acc.Increasing acc.

30. Exit Ticket What is the unit of acceleration? Solve these problems: 1. A car is traveling at a velocity of 24 km/hr west and increases to a speed of 50 km/hr west in 4 seconds. What is the car’s acceleration? 2. Jada is walking to the store at a velocity of 5 km/hr. She realizes that the store is closing in a few minutes. She accelerates to running at a rate of 15 km/hour in 2 seconds. What is her rate of acceleration?