2. What are Newton’s Laws of Motion? I. Law of Inertia II. F=ma III. Action-Reaction

3. 1 st Law of Motion (Law of Inertia) An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.

4. 1 st Law Inertia is the tendency of an object to resist changes in its velocity: whether in motion or motionless. Inertia is the tendency of an object to resist changes in its velocity: whether in motion or motionless. More mass = more inertia More mass = more inertia This law is nicknamed the law of inertia This law is nicknamed the law of inertia These pumpkins will not move unless acted on by an unbalanced force.

5. 1 st Law Example: Example:  A golf ball will sit on the tee until acted upon by an outside force.  Once hit, it will travel until fluid friction and gravity slow it down.  IF…their was no atmosphere or gravity to slow it down it would continue on forever in the direction it was hit.

6. In your words… without peeking!!! Write out Newton’s first law What is Newton’s first law’s nickname?

7. Four main types of friction: Four main types of friction: 1. Sliding friction: 1. Sliding friction: ice skating 2. Rolling friction: 2. Rolling friction: bowling 3. Fluid friction (air or liquid): 3. Fluid friction (air or liquid): air or water resistance 4. Static friction: 4. Static friction: initial friction when moving an object What is this unbalanced force that acts on an object in motion?

8. Using only your school supplies… demonstrate each of the four types of friction with your neighbor. Sliding friction:Rolling friction: Fluid friction:Static friction:

9. Newtons’s 1 st Law and You Because of inertia, objects resist changes in their motion. When the car going 80 km/hour is stopped by the brick wall, your body keeps moving at 80 m/hour until friction and gravity slow it down and stop it.

10. Talk it out… 4 types of Friction 2 parts of Newton’s first law

11. Share one real world example.

12. 2 nd Law

13. The acceleration of an object depends on the mass of the object and the amount of force applied.

14. 2 nd Law Units: Units:  Force: Newton (N) or kg m/s/s  Mass: kilograms (kg)  Acceleration: meters per second per second (m/s/s) One Newton = force required to accelerate one kg of mass at one m/s/s. One Newton = force required to accelerate one kg of mass at one m/s/s.

15. 2 nd Law (F = m x a) How much force is needed to accelerate a 1400 kilogram car 2 meters per second/per second? Write the formula Write the formula F = m x a Fill in given numbers and units Fill in given numbers and units F = 1400 kg x 2 meters per second/second Solve for the unknown Solve for the unknown 2800 kg*m/s/s or 2800 N

16. Think… Pair… Write… Share If I drop two objects of different masses at the same time which will hit the floor first? The lighter or the heavier one? If I drop two objects of different masses at the same time which will hit the floor first? The lighter or the heavier one? If I drop two objects with the same mass, but different shapes which will hit the floor first? The smaller or larger object? If I drop two objects with the same mass, but different shapes which will hit the floor first? The smaller or larger object?

17. Newton’s 2 nd Law proves that different masses accelerate to the earth with different forces, but at the same rate. 1.Due to gravity, all objects accelerate towards earth at 9.8 m/s/s. 2.Objects with different masses accelerate to the ground at the same rate. 3.However, the greater the mass is the greater their impact is on Earth.

18. If mass remains constant, doubling the acceleration, doubles the force. If force remains constant, doubling the mass, halves the acceleration. A C B

19. 4 type of forces Gravity Gravity Electricity Electricity Magnetism Magnetism friction friction

20. Check Your Understanding 1. What acceleration will result when a 12 N net force applied to a 3 kg object? 12 N = 3 kg x 4 m/s/s 12 N = 3 kg x 4 m/s/s 2. A net force of 16 N causes a mass to accelerate at a rate of 4 m/s/s. Determine the mass. 2. A net force of 16 N causes a mass to accelerate at a rate of 4 m/s/s. Determine the mass. 16 N = 4 kg x 4 m/s/s 16 N = 4 kg x 4 m/s/s 3. How much force is needed to accelerate a 66 kg skier 2 m/sec/sec? 132 N = 66 kg x 2 m/s/s 132 N = 66 kg x 2 m/s/s 4. What is the force on a 1000 kg elevator that is falling freely at 9.8 m/sec/sec? 9800 N = 1000 kg x 9.8 m/s/s

21. Talk it out… What measurements must we know or seek out in Newton’s 2 nd law? 4 types of forces

22. 3 rd Law Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

23. 3 rd Law Think of one thing you are applying a force to at the current moment that is applying a force back. According to Newton, whenever objects A and B interact with each other, they exert forces upon each other.

24. 3 rd Law There are two forces resulting from this interaction - a force on the chair and a force on your body. These two forces are called action and reaction forces.

25. Newton’s 3rd Law in Nature Examples: Examples:  Fish propelling through the water (force on water is backward and the fish moves forward)  Stepping out of a boat onto the dock and boat moves away from the dock (person moves forward, boat moves backward)  Birds push down on the atmosphere and the air lifts them so they can to stay aloft

26. 3 rd Law Explain in a sentence what the action / reaction pair is in the scenario to the left at take-off.