2. Forces Wednesday, November 4, 2015

3. Wednesday, 11/4 Unit 4: Work and Forces  Pick up a warm-up sheet  Take out your homework from Monday (video notes)  Respond to the following on your warm-up sheet. 1. What causes an object to accelerate? 2. What is the relationship between force and acceleration? Upcoming dates  Wednesday, 11/4 – forces video notes due  Friday, 11/6 – quiz  Monday, 11/16 – quiz  Monday, 11/16 – review due at when the late bell rings  Wednesday, 11/ 18 – Unit 4 test  W/O 11/23 – Thanksgiving break  Friday, 12/11 – 2NW extra credit due

4. Simulating Inertia Part 1  Pull the index card fast and record what happens to the penny.  Roll the glue stick towards the meter sticks and record what happens to the glue stick.

5. Objects tend to stay at rest OR object tend to stay in motion at a constant speed. (Add to your video notes)

6. Inertia  Video guide questions  Give an example of an object (football player) resisting change.  What caused the object (football player)to change their motion?

7. Watch video http://www.nbclearn.com/portal/site/learn /science-of-nfl-football

8. Marking the test  Highlight the following words in the text:  Push  Pull  Force  Unbalanced force  Balanced  Gravity  Friction  Applied force  When finished highlighting complete your summary.

9. Identifying Balanced and Unbalanced Forces – 5 minutes  Work with your elbow partner to determine whether the forces will be balanced or unbalanced (the size of the vectors indicates the magnitude of the vector).

10. Newton’s 2 nd Law of Motion  Describes how an object behaves when forces are unbalanced.  Unbalanced forces results in a net force (difference in forces)  When a net force is present the object will accelerate (velocity will change in a period of time)

11. Net Force Example 1: F g = 19.6 N F app = 19.6 N 1.What is the net force? 2.What direction is the object moving?

12. Net Force Example 2: F g = 19.6 N F app = 40 N 1.What is the net force? 2.What direction is the object moving?

13. Net Force Example 3: F g = 19.6 N F N = 19.6 N 1.What is the vertical net force? 2.What is the horizontal net force? 3.What direction is the object moving? F app = 2 N F f = 2 N

14. Net Force Example 3: F g = 19.6 N F N = 19.6 N 1.What is the vertical net force? 2.What is the horizontal net force? 3.What direction is the object moving? F app = 10 N F f = 2 N

15. Net Force Practice  With your elbow partner do the following:  Add force values to your practice sheet.  Determine the net force acting on the object.  Use a colored pencil to draw a vector (vectors) to balance any unbalanced force.  Assign a numerical value to the vector’s you draw

16. Cool Down 1. If there is an unbalanced force acting on an object how will the object’s motion be affected? 2. If the forces are balanced on an object how will the object’s motion be affected?