1. Agenda 1) Warm-Up 5 min 2) Sig. Fig Worksheet Due! 3) Physics Vocab. Words 10 min 4) Acceleration Notes 20 min 5) Acceleration Board Notes 10 min 6) Acceleration video 10 min 7) Acceleration WS 20 min 09 -12- 11 1 HOMEWORK CHECK Place on your desk: *Calculator *Orange homework chart *Sig Fig WS (#1-34)

2. Vocabulary: 1.Position-time graph: graph that shows how position depends on clock reading or time. 2. Slope: ratio of the vertical separation of 2 points on a curve or rise, to the horizontal separation of the points, or run; rise divided by run; change in distance/change in time. 3. Velocity-time graph: plot of velocity of an object as a function of time.

3. Review Graphs Direct relationship graphs: Straight line---x and y axis do the same thing (increase or decrease) Inverse relationship---x and y axis do the “opposite” of each other ( i.e. x will increase and y will decrease)

4. A driver on a 2 lane road wants to pass another car. Does he want to drive slow next to the other car, speed up next to it, or go slower than it? This is… Acceleration

5. Delta (∆) = “change in …” Example-you might see ∆t, this means change in time, t f - t i

6. Acceleration Acceleration is changing velocity; either speeding up or slowing down.  ACCELERATION IS NOT VELOCITY change of velocity Acceleration = time interval

7. Acceleration is VECTOR Acceleration is a vector quantity due to the quantity of “velocity” Acceleration therefore, has magnitude and direction

8. Acceleration changes if……. Speed OR Velocity changes Direction changes (VECTOR)

9. Example 1 What is the acceleration of a car that travels in a straight line at a constant speed of 20m/s? ZERO acceleration

10. Acceleration can have a “positive” value---normally when the object is “speeding up” or -can have a “negative” value----when the object is “slowing down”  “Zero” acceleration is found when moving at a constant velocity in a straight line— same magnitude /direction

11. Graphs of Motion The slope of the line in a velocity vs time graph is acceleration. VIDEO 

13. ACCELERATION Board Notes

14. Example 2 What is the acceleration of an object that, while moving in a straight line, increases its speed from 0 to 20 m/s in 10 seconds.

15. What is the average acceleration of a car that goes from 1050 km/min to rest in 5 seconds?