1. PICK UP JOURNAL FROM COUNTER BY DOOR AND FILL OUT TABLE OF CONTENTS Table of Contents DateEntryPag e # 9/1 0 Observations Quiz 7 Unit 2: Force and Motion 9/1 0 Force Notes8

2. FORCE Objective: Students will demonstrate and illustrate forces that affect motion in everyday life

3. FORCE VIDEO http://www.youtube.com/watch?v=LEs9J2IQIZY

4. FORCES A force is a push or pull Forces give energy to objects Forces cause a change in motion (start moving, speed up, change direction, slow down, or stop)

5. FORCE FORCE – is measured in units called NEWTONS (N) Examples- a force will have the letter N behind it. 12N and 135N represent forces. FORCE is measured using a spring scale. A spring scale measures the amount of force needed to move an object. 5

6. To describe a force, you must know two things: Size of the force and Direction of the force

7. VERY IMPORTANT INFORMATION ABOUT FORCE!!! To describe a force, you must know two things: Size or strength of the force and the Direction of the force 25N Direction of Force Size or Strength of force

8. BALANCED FORCES Forces that are equal in size but opposite in direction are under balanced forces Balanced forces do not cause a change in the motion of objects

10. UNBALANCED FORCES Unbalanced Forces can cause an object to change directions or to start moving

11. UNBALANCED FORCES Unbalanced forces can change the motion of an object in two ways:  When unbalanced forces act on an object at rest, the object will move  When unbalanced forces act on a moving object, the object will change direction

12. PRACTICE PROBLEMS PLEASE COPY THE PROBLEM!!!! CALCULATING NET FORCE

13. PROBLEM A Net Force Unbalanced 225 N

14. PROBLEM B Net Force Unbalanced 75 N

15. PROBLEM C Net Force Balanced 50 N 0 N 50 N 100 N

16. PROBLEM D Net Force Unbalanced 792 N 224 N 632 N 400 N 100 N900 N + + +

17. PROBLEM E Net Force Unbalanced 550 N 13 N 750 N 1563 N 250 N + +

18. PROBLEM F Net Force Unbalanced 987,256 N 6011 N 993,267 N

19. THANK YOU! Glue your notes on page 8 Please pass down your journals!