1. D O N OW Write your HW in your agenda Update your table of contents: Have pages 152 and 153 ready to be checked Fold the notes and attach to page 155. You have 10 minutes to find and identify the types of friction on the 15 cards hidden in the room. (all can be seen without moving anything) Page #TitleDate 154(We will be using this page later in the week) 155Newton’s Laws of Motion04/13

2. N ET F ORCES The combination of all the forces acting on an object is the net force

3. C OMBINING FORCES If the forces are in the same direction, the net force is the sum of those forces. If the forces are in opposite directions, the net force is the subtraction of those forces.

4. B ALANCED FORCES AND U NBALANCED FORCES If the combined forces result in a net force of 0, this is called a balanced force. If the combined forces result in a net force that is NOT 0, this is called an unbalanced force.

7. T HIS IS N EWTON ’ S F IRST L AW OF M OTION An object at rest will remain at rest and an object moving at a constant velocity will continue at the same velocity, unless acted upon by an unbalanced force.

8. I NERTIA Whether an object is moving or not, it resists any change to its motion. This tendency to resist a change in motion is called inertia.

9. I NERTIA Inertia depends on mass, which means some objects have more inertia than others. The greater the mass of an object, the greater its inertia, and the greater force is required to change its motion.

10. Using Newton’s first law of motion, explain why the skater moved.

11. D O N OW Update notebooks and record HW. Pay attention for a challenge I am issuing you. PagesTitleDate 156Motion Misconceptions04/14 157Newton’s 3 rd Law04/14

12. Which requires more force to move- a heavier object or a lighter object? N EWTON ’ S S ECOND L AW OF M OTION

13. States that… The acceleration of an object depends on the object’s mass and on the net force acting on the object. N EWTON ’ S S ECOND L AW OF M OTION

14. This relationship between force, mass, and acceleration can also be written as an equation. F=ma N EWTON ’ S S ECOND L AW OF M OTION

15. UNITS!

16. A speedboat pulls a 55-kg water- skier. The force causes the skier to accelerate at 2.0 m/s 2. Calculate the net force that causes this acceleration. Force= 55kg * 2.0m/s 2 Force=110N P RACTICE P ROBLEM

17. E XIT S LIP You are sitting in a moving car and the driver suddenly pushes down on the brake. 1. Describe your motion if you were wearing a seatbelt. 2. Describe your motion if you weren’t wearing a seatbelt. 3. Which law of motion does this situation relate to?