1. Chapter 2-Sec 3 & Chapter 3

2. Warm-up 2/14/13  Teach the Teacher: Valentines Day: love or hate and why?  Review: What is instantaneous speed?

3. What causes things to move the way they do?

4. Forces   Force —a push or pull that one body exerts on another

5. Balanced Forces   Net Force —when 2 or more forces act on an object at the same time   Balanced Forces —forces that are equal in size and opposite in direction. – –An object will remain still

6. Unbalanced Forces   Unbalanced Forces —The size and direction of forces acting on an object are unequal. – –cause objects to move.

7. Balanced & Unbalanced Forces

8. Warm-up 2/15/13  Teach the Teacher: What was the hardest thing you have ever had to do?  Review: If I pull a bowl of macaroni and cheese across the room, is that a balanced force or unbalanced?

9. Flash Card  On the Front write:  Force  On the back write: –is a push or a pull –can give energy to an object causing motion

10. Inertia   Inertia —the tendency of an object to resist a change in its motion – –Velocity of an object only changes if a force changes it.   The inertia of an object is related to mass – –The greater the mass, the greater its inertia.

11. Newton’s 1 st Law of Motion   Newton’s 1 st Law: The Law of Inertia – –An object at rest stays at rest and an object in motion stays in motion with the same speed and direction unless acted on by an unbalanced force.

12. Warm-up 2/19/13  Teach the Teacher: How many presidents can you think of?  Review: How many different ways can you describe motion (think of the different triangles and graphs that we looked at)

13. Flash Card  On the front write:  Inertia  On the back write:  The resistance of an object to a change in its state of motion.

14. What Galileo did:  Galileo's Experiment Galileo's Experiment Galileo's Experiment

15. The ball would roll forever….. Like in space Like in space Like in space

16. Newton’s 1 st Law of Motion

17. Punkin Chunkin: Inertia II  Punkin Chunkin: Inertia Punkin Chunkin: Inertia Punkin Chunkin: Inertia  http://www.youtube.com/watch?v=Xynn81pp 9tg http://www.youtube.com/watch?v=Xynn81pp 9tg http://www.youtube.com/watch?v=Xynn81pp 9tg

18. Shooting Objects at Rest The object’s inertia causes it to remain still even when a bullet passes through it.

19. Friction   Friction: A force that opposes motion between two surfaces that are touching each other   The amount of friction is dependant upon – –Surfaces – –Force pressing the surfaces together

20. Types of Friction   Static Friction – –Friction between two objects that are NOT moving.   Sliding Friction – –Friction between two surfaces moving past each other.   Rolling Friction – –Friction between a rolling object & the surface it is rolling on.   Fluid Friction – –Friction between an object and a gas or liquid

21. Air Resistance   Air Resistance: Collisions of the object's leading surface with air molecules.   Dependent upon a variety of factors, most importantly –the speed of the object  Increased speeds = increased air resistance. –the cross-sectional area of the object  Increased cross-sectional area=increased air resistance

22. PTW:Air Resistance Challenge  Put your name on both sheets of paper  One sheet=design a “papercraft” that will have A LOT of air resistance  Other sheet=design a “papercraft” that will have VERY LITTLE air resistance  WHEN DROPPED FROM THE SECOND STORY BALCONY  YOU WILL FAIL IF YOU DON’T PICK IT UP!

23. PTW: Air Resistance Challenge  1. Why did your A LOT of air resistance design work or not work?  2. Why did your VERY LITTLE air resistance design work or not work?  3. What would make a sky diver slow down? What would make them speed up?

24. Warm-up 2/20/13  Teach the Teacher: What is the best kind of fruit?  Review: What has more inertia, string cheese or a puppy?  NO LIQUIDS OR GELS (INCLUDING PEANUTBUTTER) or ANYTHING STICKY for EGG DROP!

25. Flash Card  On the front write:  Newton’s First Law  On the back write:  Objects at rest stay at rest….  Objects in motion stay in motion…. unless acted on by another force

26. PTW: Keep the Change  http://www.nbc.com/minute-to-win-it/how- to/keep-the-change/ http://www.nbc.com/minute-to-win-it/how- to/keep-the-change/ http://www.nbc.com/minute-to-win-it/how- to/keep-the-change/  The Challenge: Design an inertia demonstration and present why it demonstrates inertia/Newton’s first law.

27. PTW: Keep The Change  Jobs: Recorder, Presenter 1, 2, 3 (some people might have to do more then one)  1. What is inertia? What is Newton’s First Law  2.What did you do to demonstrate inertia/Newton’s first law?  3. How does the demonstration show inertia/Newton’s first law?

28. Warm-up 2/21/13  Teach the Teacher: When is a time that you have laughed at yourself?  Review: What kind of speed is measured from a total distance divided by the total time?

29. Flash Card  On the Front:  Balanced Forces  On the Back:  Forces that are equal in opposite directions = no movement

30. Flash Card  Front:  Unbalanced Forces  On the Back:  One force being larger than the other in opposite directions = movement

31. Newton’s Second Law   Newton’s 2 nd Law: The acceleration of an object is dependent upon the force acting upon the object and the mass of the object.   Newton’s Second Law as an equation: F = m × a   F = force (N) Newton is the SI Unit of force   m = mass (kg) N = kg m / s 2   a = acceleration (m/s/s)

32. Units  The SI unit for mass =kilogram (kg)  The unit for acceleration = meters per second squared (m/s 2 )  So the unit for force = kg x m/s 2  The kg x m/s 2 is called the newton (N)

33. Tugboat Problems  Two tugboats are moving a barge. Tugboat A exerts a force of 3000 Newtons on the barge. Tugboat B exerts a force of 5000 Newtons in the same direction. What is the combined force on the barge? Draw arrows showing the individual and combined forces of the tugboats.

34. Tug Boat Questions  Now suppose that Tugboat C exerts a force of 2000 Newtons on the barge and Tugboat D exerts a force of 4000 Newtons in the opposite direction. What is the combined force on the barge? Draw arrows showing the individual and combined forces of the tugboats.

35. Warm-up 2/22/13  Teach the Teacher: What will be the best thing about being an adult that has graduated from high school?  Review: What kind of friction is caused by socks rubbing on the carpet?

36. Flash Card  On the front write:  Air resistance  On the back write:  A force on objects as they fall through the air.

37. Flash Card  On the front write:  Newton’s 2 nd law  On the back write:  Acceleration of an object depends on the mass and force  F=ma

38. Warm-up 2/25/13  Teach the Teacher: Do you think you will be a parent some day? If so, how do you want to be like your parents/guardians?  Review: What is the force that is caused by air pushing up on an object as it falls?

39. Flash Card  On the front write:  Mass  On the back write:  The amount of matter in an object, doesn’t change (units=g and kg)

40. Warm-up 2/26/13  Teach the teacher: What is the “secret ingredient” for an egg drop container?  Review: What is the units for force?

41. Warm-up 2/27/12  Teach the Teacher: If you could break the world record in something, what would you want to break it in?  Review: What is the unit for acceleration?

42. Flash Card  On the front write:  Gravity  On the back write:  An attractive force between two objects depend on the mass and distance

43. Gravity  Universal law of Gravity: – –Any 2 objects will exert an attractive force on each other – –The size of the force is dependant on 2 things   Mass of both objects   Distance between the objects – –The range of gravity never disappears   Therefore it is not possible for an object with mass to be weightless.

44. Weight vs. Mass   Weight: Force of gravity pulling you toward the earth – –F = ma becomes W = mg – –Weight = mass × gravitational acceleration   g on Earth is 9.8m/s 2 – –SI Unit = Newton – –Weight can change with a change in location.   Mass: A measure of how much matter an object has – –You know an object has mass because it has inertia – –SI Unit = Kilograms

45. CentripetalForce Centripetal Force   Centripetal Force: The force exerted toward the center of a curved path.   Earth’s gravity exerts a centripetal force on the Moon that keeps it in a nearly circular orbit.   Real World/space station & centripetal force Real World/space station & centripetal force   Roller coaster Loops Roller coaster Loops

46. Warm-up 2/28/13  Teach the Teacher: Would you rather eat worms or mold?  Review: What is the circular force called when something spins in a circle?

47. Flash Card  On the front write:  Weight  On the back write:  The force of gravity pulling on you, changes in the universe

48. How to Do Space Weight

49. The last questions

50. Falling Objects on Earth   Near Earth’s surface acceleration due to gravity is 9.8 m/s 2   If 2 objects with different masses are dropped from the same height, which would hit the ground first? http://www.youtube.com/watch?v=aRhkQTQxm4w &feature=plcp dropping objects on the moon

51. Projectile Motion   Anything dropped, thrown, or shot through the air is a projectile   Because of gravity and inertia, you can get a curved path. http://video.pbs.org/video/1602463762/ http://science360.gov/obj/tkn-video/fc729ef0-22ee-4f61-bb2a-b6c07685fb02/science-nfl- football-projectile-motion-parabolas

52. Monkey and the Zookeeper   The zookeeper must shoot the banana from the banana cannon to the monkey who hangs from the limb of a tree.   This particular monkey has a habit of dropping from the tree the moment that the banana leaves the muzzle of the cannon.   The zookeeper is faced with the dilemma of where to aim the banana cannon in order to hit the monkey.   If the monkey lets go of the tree the moment that the banana is fired, then where should she aim the banana cannon?

53. Monkey and the Zookeeper Where should the zookeeper aim? Taking Gravity into effect The zookeeper aims above the monkey Does the speed of the banana change the effect? The zookeeper aims at the monkey and shoots the banana very fast The zookeeper aims at the monkey, yet shoots the banana very slow. ZOO in SPACE In a low gravity environment, where should the zookeeper shoot the banana?

55. Physics To Win It  Hole in One  Challenge: To roll a golf ball off the ramp, off the table, and land in the cup…I have to see it.  Jackpot challenge: To get a golf ball to do the above, bounce once and land in the cup  On an index card calculate the velocity of the ball

56. NEWTON’S 3 rd LAW: NEWTON’S 3 rd LAW: For every action, there is an equal and opposite reaction   “ Action” and “Reaction” are names of forces   Forces ALWAYS occur in pairs   Single forces NEVER happen

57. “ Equal & Opposite ”   In Newton’s 3 rd Law, “equal” means:   Equal in size   Equal in time. – –occur at EXACTLY the same time.   In Newton’s 3 rd Law, “opposite” means:   Opposite in direction –forces are EXACTLY 180 o apart in direction.  Only forces that act on the same object can cancel.  Newton’s 3 rd Law action and reaction forces act on different objects, so they DON’T cancel.

58. Writing Action Reaction Forces – –ACTION Bowling ball hits the pin to the left. – –REACTION Pin hits the bowling ball to the right

60. Momentum:   A property of how much force is required to change the object’s motion – –The object’s mass times its velocity   p = mv – –p = momentum – –m = mass – –v = velocity   SI UNIT = Kg m / s

61. Law of Conservation of Momentum   Momentum may be transferred to another object   The total momentum before a collision is equal to the total momentum after the collision   m 1 v 1 = m 2 v 2

62. Physics To Win it Challenge  Back Flip Back Flip Back Flip  1.Draw a diagram of the forces working on your hand and pencil BEFORE the flip  2. Draw a diagram of a the forces working on your hand and pencil DURING the flip

63. Types of Collisions   Elastic collisions –the total kinetic energy before the collision is equal to the total kinetic energy after the collision. –Usually the objects bounce off of each other.

64.   Inelastic collisions – –the total kinetic energy before the collision is NOT equal to the total kinetic energy after the collision. – –Usually the objects stick together interactive

65. The Truck and The Ball   A pickup truck is moving with a constant speed.   In the course of its motion, a ball is projected straight upwards by a launcher located in the bed of the truck.   Assume the ball does not encounter a significant amount of air resistance.   What will be the path of the ball and where will it be located with respect to the pickup truck?

66.   Many would insist that there is a horizontal force acting upon the ball since it has a horizontal motion.   Yet this is simply not the case. The horizontal motion of the ball is the result of its own inertia.   When projected from the truck, the ball already possessed a horizontal motion, and thus will maintain this state of horizontal motion unless acted upon by a horizontal force.   An object in motion will continue in motion with the same speed and in the same direction... (Newton's first law).

67.  Newton's Law Review Newton's Law Review Newton's Law Review  physclips newton's laws physclips newton's laws physclips newton's laws  http://www.phys.unsw.edu.au/einsteinlight/ http://www.phys.unsw.edu.au/einsteinlight/