2. Newton’s Laws of Motion Newton has three laws that explain the way things move.

3. Newton’s First Law Newton’s 1 st Law – the Law of Inertia- An object at rest will stay at rest unless acted on by an unbalanced force. An object in motion will stay in motion (in the same direction and at the same speed) unless acted on by an unbalanced force.

4. Newton’s Second Law Force = Mass x Acceleration The heavier an object is, the more force required to move it.

5. Newton’s Third Law For every action there is an equal and opposite reaction

6. Newton’s 1 st Law The soccer ball stays at rest until the player kicks it- it moves until the grass, or another player stops it

7. Newton’s 2 nd Law It would take more force to move an elephant than it would to move a mouse

8. Newton’s 3 rd Law The gases coming out of the rocket push on the atmosphere which pushes back at it with equal and opposite reaction – allowing the rocket to move into space

9. How far you travel along a path while you change position is….

10. Speed is the distance an object moves in a certain amount of time. Speed = Distance Time

11. We use speed to measure the motion of objects. An object may be moving at a slow rate or at a fast rate.

12. A horse can run 120 meters in 6 seconds. What is the speed of the horse?

13. Velocity Speed of an object in a given direction. Different from speed because speed only tells how fast an object is moving. Velocity includes both speed and direction. Example: a plane’s velocity is 6000km/h south

14. Tells how fast an object changes its velocity. When an object is speeding up, it is accelerating. When an object is slowing down it is also accelerating. Slowing down is sometimes called negative acceleration or deceleration. An object is not accelerating when it travels in a straight line at a constant speed or when it sits at rest.

15. A train sitting in a station (is or is not) accelerating. Traveling at 100km/hr on a straight stretch of track (is, is not) accelerating Pulling out of the station? Slowing down as it pulls into a station?

16. Force and motion describe everyday things that are happening all the time. 1. Did you pick up a pencil? 2. Did you turn a page? 3. Raise your hand? 4. Pack your backpack? All these are examples of force and motion!

17. Change in position relative to fixed objects Moving from one place to another

18. An object an observer uses to detect motion.

19. Push or pull When you throw a baseball, you are pushing it through the air. When you pick up a baseball you are pulling it up from the ground.

20. To describe a force, we must know two things. Its SIZE AND Its DIRECTION.

21. The force being applied by each team in a tug of war game is in opposite directions. Red team pulls to the right. Yellow team to the left. Suppose that the force applied by each team is equal in size. Then each team is pulling equally hard, but in opposite directions. Will the rope move?

22. Balanced forces: Two forces that are equal in size and opposite in direction. When balanced forces act on an object at rest, the object does not move.

23. Balanced Force Push as hard as you can against a solid brick wall. The wall doesn’t move. It pushes back with a force equal in size and opposite in direction to your push.

24. Unbalanced forces Change the motion of the object they act upon. 1. Can make an object speed up 2. Can make an object slow down 3. Can change the object’s direction

25. In tug of war what would happen if two members of the yellow team fell down and let go of the rope? The forces would not be balanced. The size of the force of the red team would be greater.

26. Types of Forces Contact Friction Gravitational Magnetic Electrical

27. What is the difference between socks and sneakers? Sneakers have a lot more friction than socks In your socks you can slide a long way down the hall. In your sneakers you can get a running start and stick to the floor.

28. Happens when two things rub together. Makes it difficult for an object to move across a surface Effect is usually to slow you down. Will a car move faster on a smooth surface or a rough surface?