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What similar action is involved in all of the following activities?

What similar action is involved in all of the following activities?. You pedal a bicycle to start moving then apply the brakes to make it stop moving. You hit the accelerator (gas pedal) to make a car speed up after the light turns green, then you hit the brakes to stop for the next red light.

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What similar action is involved in all of the following activities?

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  1. What similar action is involved in all of the following activities? • You pedal a bicycle to start moving then apply the brakes to make it stop moving. • You hit the accelerator (gas pedal) to make a car speed up after the light turns green, then you hit the brakes to stop for the next red light. • A spring pushes a marble to accelerate it out of your launcher. • You push a baseball to speed it up for a throw. A friend then pushes on the ball after it enters her glove to slow it down and catch it. Newton’s 1st and 2nd Law 1

  2. To hypothesize anything you must find patterns in data. • To obtain the data you must conduct observation experiments • Like all experiments, this must have methods, analysis of assumptions, and analysis of error/uncertainty. Hypothesis… • Must be based on the pattern you devise from all data from all observation experiments. • Must use multiple representations and usually as variables in an equation (proportional relationship between physical quantities). Science Method Recap 2

  3. Hypothesize how pushes and pulls change motion of different masses. Materials (every single material MUST be used… this means you should design multiple experiments) • Mass scale • Your muscles (you lift things up and put them down… grarghhh!!!!!) • Big ball (bowling/medicine) *1kg=2.2046lbs on Earth* • Medium ball (tennis/baseball) • Small ball (marble) • Stopwatch • Meter stick Newton’s 1st and 2nd Law 3

  4. Hypothesize how two things push or pull on each other. Materials: 2 bathroom scales 2 spring scales 2 scooters Newton’s 3rd Law 4

  5. Jackie exerts a 9.8 N force upward on a 1 kg snowball on Earth. Draw this situation focusing on the snowball. Newton’s 3rd Law 5

  6. Jackie exerts a 9.8 N force upward on a 1 kg snowball on Earth. Draw this situation focusing on Jackie’s hand. Newton’s 3rd Law 6

  7. Make a chart of representations for Newton’s Laws which includes Math, Words, Diagram, and Example. Newton’s Laws 7

  8. Make a diagram with force vectors for a box sitting stationary on the ground. Force Diagrams 8

  9. Make a force diagram for 3 stationary, stacked boxes. The most massive box is on the bottom and the least is on the top. Use a separate diagram for each box as the system and one for all three as the system. Force Diagrams 9

  10. Make a force diagram for a box being pushed on a rough surface but remaining stationary. Force Diagrams 10

  11. Make a diagram for a box being pushed along a rough floor at a constant velocity. Force Diagrams 11

  12. Make a diagram for 2 boxes (top 3kg, bottom 5 kg) stacked vertically and being pushed horizontally along a rough floor at a constant velocity. Force Diagrams 12

  13. A 2000 kg car sits on a 60o hill in San Francisco. What is Fstaticfriction on car? Force Diagrams 13

  14. Predict to test Newton’s Laws Materials: phet.colorado.edu ‘Forces and Motion’

  15. Hypothesize how friction operates on a subatomic scale.Materials: phet.colorado.edu ‘Friction’

  16. Hypothesize the relationship between the friction force of the floor on your shoe and the amount of normal force exerted by the floor on your shoe. Friction Force 16

  17. If a 3500kg object rests on a hill with a 37o slope and is stationary, what is µstatic? Friction Force 17

  18. If a 3500kg object slides on a 37o slope and is µkinetic = 0.004, what is this object’s motion? Friction Force 18

  19. Hypothesize the relationship between the force used to stretch a spring and the distance it is stretched. Spring Force 19

  20. Spring, Tension, and Friction Force 20

  21. 4 kg µkinetic = 0.02 alarge = ? Assumptions? 12 kg Spring, Tension, and Friction Force 21

  22. Hypothesize using the following materials: String Pulleys Masses Balloons (Helium and Atmosphere) Springs Measuring Devices Scientific Method for Forces 22

  23. Hypothesize a quantitative model for the force which moves objects in circles. Materials: ball on a string Central Force 23

  24. central force

  25. Meghana spins a ball around her head on a string. The velocity of the ball is 5 m/s, the ball has 1.3 kg of mass, and the radius of the circle she is spinning is 2m. Draw a diagram of this situation with all necessary physical quantities including the central force and acceleration.Then draw this same situation for:1) Doubled velocity2) Halved radius3) A ball 4 times larger***Make sure to create multiple representations and list assumptions.*** Central Force 25

  26. It takes 34s for Vidya to do a full circle doughnut in a snowy parking lot with his car. The lines in the snow from the car are 10m wide. What is the circular acceleration of car while it is doughnuting. Central Force 26

  27. Mr. Mayes is swinging a bucket of water above his head. The bucket and the water is 10kg. Mayes’ total wingspan is 78 inches and it takes him 2 seconds to spin the bucket. Create force diagrams for the top and the bottom of the motion. Central Force 27

  28. Indiana Jones has a 3kg mass at the end of his 3m long whip to fight the UngaBunga tribe of cannibals. What does he have to do with his whip to stun them with 100 N of force? If he has to stun the tribal chief which takes 9 times the force, what will he have to do? Central Force 28

  29. Hypothesize the relationship between the quantities which determine the gravitational force between two objects.Materials: phet.colorado.edu‘Gravity Force Lab’ Gravitational Force 29

  30. You are wearing a winter coat while riding on a subway. You notice the strands on your jacket are being pulled toward the plastic seat on the subway car after rubbing around for a while. When you get up from the seat, you feel that the seat is pushing against the glass surface of your watch/phone/computer also.What in the name of all that is sweet and good is this skullduggery? Electric Force 31

  31. Hypothesize the quantitative nature of the electric force using the following:‘Balloon and Static Charge’ phet.colorado.eduPolarity shift game on The Universe and More Electric Force 32

  32. Electric Force 33

  33. Create a Venn diagram or chart comparing gravitational force to electric force. Distance Forces 34

  34. What is the electric force between the proton and electron in the Bohr model of hydrogen? A: 8 x 10-8 N What is the gravitational force between Earth and Sol (the sun)?A: 3.5 x 1022 N Electric Force 35

  35. Make a Venn diagram comparing Motion (Kinematics) and Forces (Dynamics). 1 D Momentum 36

  36. Consider the following: A softball is pitched underhand. 2. The driver of an Abrams tank hits the gas. If they both have the same final velocity and acceleration to get to that final velocity, what is different about these two scenarios? How would the force and motion diagrams for these two compare? How could we account for this? 1 D Momentum 37

  37. You have bowling balls, pool balls, tennis balls, and golf balls. Create experiments to observe what happens during various collisions. Invent a physical quantity to communicate these situations. Keep in mind this physical quantity must combine the factors unique to motion and forces respectively. 1 D Momentum 38

  38. Hypothesize the aspects of this new physical quantity (momentum).Design experiments using: 1. pool ball and a golf ball2. phet.colorado.edu ‘collision lab’Make sure to identify the independent, dependent, controlled, and confounding variables. Include assumptions and error. 1 D Momentum 39

  39. Summary of Momentum • P=mV units are kg(m/s) • Impulse changes momentum J=mΔV=FΔt • Momentum can be transferred from one object to another. • Momentum is conserved if there is no impulse (outside force exerted in a change in time) exerted on the system ΣPi + J = ΣPf • Collisions can be described as inelastic (sticky) or elastic (bouncy) • Momentum is described with diagrams, math(s), and bar charts 1 D Momentum 40

  40. Create bar graphs to chronicle the following scenario. • You have no money in your pocket, $60 in your ATM account, and a gift card with $20 on it. You withdraw $20 cash from the ATM. • Next, you buy a lemons and a pitcher for $10 cash at Jones Grocery. (The initial state for this process is the same as the final state of the previous process.) • After returning from the grocery store, you make lemonade and manage to sell enough to make $10. • When you are finished selling lemonade, you spend $20 cash to put gas in your car so you can drive to Target. • At Target, you purchase the new Super Mario Brothers game for Wii for $50. You empty out your gift card and use your ATM card to pay for the rest. Conservation of Momentum Bar Graphs 41

  41. A 70.0 kg man and his 40.0 kg daughter on skates stand stationary together on a frozen lake. If they push apart and the father has a velocity of 0.50 m/s eastward, what is the velocity of the daughter? (neglect friction) Include a momentum bar graph and other necessary representations. Momentum 42

  42. The velocity of a 6.00 x 102 kg elephant is changed from 10.0 m/s to 44.0 m/s in 68.0 s by a constant force from a truck which is shipping it. What is the impulse on, force exerted on, and acceleration of this object? Do this in as many ways as you can think of. Momentum 43

  43. Before Analyze this scenario in terms of momentum. Analyze this scenario in terms of forces and motion. 5 kg 3 kg 2m/s After 5 kg 0.5m/s 3 kg ?m/s Momentum 44

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