1.  Vocabulary  Acceleration: The rate at which velocity changes  Constant acceleration: A steady change in velocity  Announcements:

2. Science 8 th Grade

3.  S8P3. Students will investigate relationship between force, mass, and the motion of objects.  a. Determine the relationship between velocity and acceleration. (DOK 2)

4.  It is a rate!  Let’s try this one more time…what is a rate?  Right…right…  What is changing?  Velocity  Standard unit: meters per second squared (m/s 2 )

5.  Speed!  Positive acceleration  Positive change in speed  Increase speed  Negative acceleration  Negative change in speed  Decrease speed

6.  Speed and direction  Yes, changing at the same time.

7.  From the vocabulary, we know it is steady change in velocity  Essentially, a constant rate change in velocity  Or…velocity is changing the same amount each second  www.youtube.com /watch?v=BGfPU_g yqm8 www.youtube.com /watch?v=BGfPU_g yqm8

8.  a = v f – v i t  a – acceleration  v f – final velocity  v i – initial velocity  t – time  Units?  Try some problems.

9. 1. A car traveling at 10 m/s starts to decelerate steadily. It comes to a complete stop in 20 seconds. 2. An airplane travels down the runway for 4.0 seconds with an acceleration of 9.0 m/s 2.

10.  Demonstrated on a speed vs. time graph  The slope demonstrates acceleration  Or…increasing or decreasing slope of distance-time graph

11.  Explain how acceleration is considered a rate?  It is a vector too… what does that mean?  What kind of graph shows acceleration?