Forces and Motion in Physics: Understanding Newton's Laws

1. SCIENCE Benchmark REVIEW Good Luck Bulldogs! You Can "Do it"!

2. Remember you can only have one independentvariable in an experiment.(The thing you are testing and change). The independent variable goes on the x-axis when graphed. • All other parts of the experiment must remain the same (Constants) • The result you MEASURE is called the Dependentvariable. The dependent variable goes on the y axis when graphed.

3. Motion & Forces Amusement Park Forces

4. Physics 8.6a- Demonstrate and calculate how unbalanced forces change the speed and direction of an objects motion. Activities: Gizmo: Force and Fan Carts Lab: Car ramps (clay on string, and added weight to car) Lab: Newton’s Cart lab: Pennies in film canister and you burned the string

5. What is a Force? FORCE = Any push or pull which causes something to move or change its speed or direction

6. What is a Force? Forces can be BALANCED or UNBALANCED • Balanced forces are equal in size and opposite in direction • unbalanced forces are not equal in size and/or opposite in direction. If the forces on an object are UNBALANCED, we say a NET force results. Amusement Park Forces

7. Friction is a Resistance Force Friction = A force that opposes or slows down motion • Caused by the physical contact between moving surfaces • The amount of friction depends upon the kinds of surfaces and the force pressing the surfaces together • Changes motion into heat

8. If you have 30N of force pulling left and another 20N of force pushing left, what is the total amount of force and in which direction? 50 N to the Left. What would be the best description of the net force between a woman and the chair she is sitting in? 0N – because the forces are balanced

9. What is the net force on the box below? 5N right Luis pushes a toy race car down the floor to the left with 5N of force. Jonathon then pushes the race car in the same direction with another 6N of force. Which direction did the race car move and with how much force? 11 N left

10. What is Friction? What are some ways athletes uses friction?

11. Forces affect Motion: • They can make objects start moving. • They can make objects move faster. • They can make objects move slower. • They can make objects stop moving. • They can make objects change direction. • They can make objects change shape.

12. Physics 8.6b- Differentiate between speed, velocity and acceleration Activities: -Motion detector Lab -Catch the Cheetah graph matching

13. What is Motion? Motion: A change in position of an object compared to a reference point Motion involves all of the following:

14. What is Motion? Distance Time

15. Distance Time 50/20 = 2.5 cm/sec

16. What is Motion?

17. What is Motion?

18. The graph shows an object which is not moving (at rest). Interpret The Graph Below:

19. The objects are moving at a constant velocity- a is moving faster than b because it has a greater slope Interpret The Graph Below: a b

20. an object moving with constant velocity towards you Interpret The Graph Below:

21. Curve line up shows acceleration Interpret The Graph Below:

22. Curve lines up show acceleration –in Red and Deceleration in black Interpret The Graph Below:

23. The graph showsthat the objects velocity does not change as time passes. It shows constant velocity. Interpret The Graph Below:

24. The graph showsthat the objects velocity is increasing as time passes – it is accelerating. Interpret The Graph Below:

25. Newton's Laws of Motion 8.6c-Investigate and describe application of Newton’s Laws of Motion Activities: -Lab Stations- roller coaster, film canister rockets, crash car with toy doll, and putting golf balls - Force, mass and acceleration of a BB and marble -Newton’s Cart Lab-

26. Newton's Laws of Motion First Law(Law of Inertia): An object at rest stays at rest or an object in motion, stays in motion (in the same direction/at the same speed) unless acted upon by an unbalanced force

27. Inertia • The tendency of an object to resist any change in its motion • The greater the mass the greater the inertia • The greater the speed the greater the inertia

28. Examples of Newton’s 1st Law(do not copy) a) car suddenly stops and you strain against the seat belt b) when riding a horse, the horse suddenly stops and you fly over its head c) the magician pulls the tablecloth out from under a table full of dishes d) the difficulty of pushing a dead car e) lawn bowling on a cut and rolled lawn verses an uncut lawn f) car turns left and you appear to slide to the right

29. Newton's Laws of Motion Second law (Law of Force and Acceleration): • The greater the force, the greater the acceleration • The greater the mass, the greater the force needed for the same acceleration • Calculated by: F = ma • (F = force, m = mass, a = acceleration)

30. Examples of Newton’s 2nd Law of Force and Acceleration(do not copy) a) hitting a baseball, the harder the hit, the faster the ball goes b) accelerating or decelerating a car c) The positioning of football players - massive players on the line with lighter (faster to accelerate) players in the backfield d) a loaded versus an unloaded truck

31. Newton's Laws of Motion Third law (Law of Action-Reaction): For every action force, there is an equal and oppositereaction force. (Forces are always paired)

32. Examples of Newton’s 3rd Law • rockets leaving earth • guns being fired c) two cars hit head on d) jumping out of a boat onto the dock

33. Examples of Newton’s 3rd Law

34. Potential Energy (PE)- Energy of position Kinetic Energy (KE)- Energy of motion

35. Always check the margin titles of any graph to help you answer questions. Speeding up or accelerating Moving at a steady Rate or pace Speed (m/s) Distance (m) Moving at a steady Rate or pace Not moving Time (sec) Time (sec)

36. Chemistry 8.5a- Describe the structure of atoms, including the masses, electrical charge and locations, of protons, and neutrons in the nucleus and electrons in the electron cloud. Activities: -Building atom models - Drawing Bohr models and building the periodic table

37. Atomic # (# of Protons) 14 Si Silicon 28.086 Element Name Element Symbol Atomic Mass (# of Protons + # of Neutrons)

38. 3 of 4

40. 1st=2 2nd=8 3rd=8

42. 13!

43. Atomic Mass 26.982 -- Atomic Number 13 = 14

44. 8.5b- Identify that protons determine an elements identity and valence electrons determine its chemical properties including reactivity. Groups Protons = atomic number=elements identity

45. Group # = # of Valence Electrons Look at the number in front of the A

46. Group # = # of Valence Electrons Elements in the same group have similar properties and reactivity because they have the same valence. A stable valence is 8 for all elements except Hydrogen and Helium. A stable valence for these elements is 2. As you move down the group elements become more reactive because they have more electron energy levels. The electrons are farther away from the nucleus. Group 18 is unreactive because all elements have a full valence shell!!

47. METALLOIDS METALS NONMETALS

48. 8.5c-interpret the arrangement of the periodic table, including groups and periods, to explain how properties are used to classify elelments Groups= valence electrons Periods Tells the # of electron rings

49. 8.5e- investigate how evidence of chemical reactions indicate that new substances with different properties are formed. Activity: Lab: Evidence of chemical reactions. Chemical Reactions Chemical Property- ability of an element or compound to react with another substance. Key words: oxidation, reactivity, flammability

50. Clues that indicate a chemical reaction: • The production of a gas. Evidence: bubbles, odor • A Change in temperature (can be an increase or decrease) • Production of a precipitate- (makes a solid, often looks like a powder) • A color change- Clear + Clear = different color