Unit 5: Physics in Action

1. Unit 5: Physics in Action

2. Essential Questions • What is inertia, acceleration, and gravity? • What are Newton’s 3 Laws of Motion and how can they be applied to everyday principles? • How does a person’s center of mass effect their balance and performance? • What is vertical accelerated motion and how can this be applied to athletic jumping? • How does the surface effect the force due to friction, and how does this affect an athlete’s performance? • What is momentum and how is it conserved?

3. Chapter Challenge – Due January 30 • You will need to find a 2-3 minute sports clip (can be recorded from TV or downloaded from the internet) of a sport that you enjoy watching/participating in • You may work individually or with a group (max. 3 people) • You will explain the physics principles behind the sport clip by either: • Submitting a written script • Performing a live narrative • Dubbing onto the video soundtrack • Recording on file

4. Day 1: A running Start • Learning Objectives: • Understand and apply Galileo’s Principle of Inertia • Understand and apply Newton’s First Law of Motion • Recognize inertial mass as a physical property of matter

5. Starter • Watch the following videos and answer the questions: • What determines the amount of horizontal distance a basketball player travels while “hanging” to do a slam dunk during a fast break? • How do figure skaters keep moving across the ice at a high speed for long periods of time while seldom pumping their skates? • Time: 15 minutes

8. Activity 1 • Newton’s First Law of Motion • Place some water in a plastic beaker. • Place a piece of paper under the beaker. • Try to remove the paper without spilling any water • Try this again using a different amount of water. Any change? • Create a definition for Newton’s first law of motion based on what you observed • Time: 20 minutes

9. Activity 2 • Make a target on a piece of paper • You are going to try to hit the target with a tennis ball as you run past it • Make any changes to your definition for Newton’s first law of motion based on what you observed • Time: 20 minutes

10. Activity 3 • Complete steps 1-4 on pages 5 & 6 • Record your data in a table you create • Time: 25 minutes

11. Closing & homework • What does Newton’s First Law of Motion state? • Why is a ball’s return height not a mirror image when you roll it down a ramp? • For you to read/Physics talk, page 8-12 • Physics to go, pg. 13 # 1, 4, 5, 6, 8, 9

12. Day 2: Adding vectors • Learning Objectives: • Recognize that a force is a push or pull • Identify the forces acting on an object • Determine when the forces on an object are either balanced or unbalanced • Calibrate a force meter in arbitrary units • Use a force meter to apply measured amounts of force to objects • Compare amounts of acceleration semi-quantitatively • Understand and apply Newton’s Second Law of Motion • Understand and apply the definition of the newton as a unit of force • Understand weight as a spatial application of Newton’s Second Law

13. Starter • What is a force? • What is Newton’s Second Law of Motion? • If you apply the same amount of force to the shot put and the tennis ball, • Will they move the same distance? • Will one ball move farther than the other? • Why? • Time: 15 minutes

14. Activity 1 • Choose 4 various masses and record their weight in newtons. Check that the mass is correct by taking the mass on the electronic scale. • How will acceleration be calculated? • What do you notice about the acceleration of each mass? What does this number represent? • Time: 25 minutes

15. Activity 2 F = ma a = F/m • Take a coffee mug and find its mass • Slide the coffee mug across the table at a slow, constant speed. Record the force used to pull the mug. • Repeat, this time sliding the mug at a faster rate. Record the force used to pull the mug. • Calculate the acceleration in both cases. What conclusion can you make? • Time: 15 minutes

16. Activity 3 • We will go to the computer lab to go through 2 activities: • http://www.bbc.co.uk/bitesize/ks3/science/energy_electricity_forces/ • Go to “Forces” and do the “revise”, “activity”, and “test” • http://learner3.learner.org/interactives/parkphysics/bumpercars/ • Work through the bumper car problems • Time: 30 minutes

17. Closing & homework • Read physics talk/for you to read, Pg. 18-22 • Physics to go, Pg 23. #1, 2, 5, 9 • Choose any 3 calculation questions from #3, 4, 11-18

18. Day 3: Center of Mass • Learning Objectives: • Locate the centre of mass of oddly shaped 2-D objects • Infer the location of the cenre of mass of symmetrical 3-D objects • Measure the approximate location of the centre of mass of body • Understand that the entire mass of an object may be thought of as being located at the object’s centre of mass

19. Starter • Watch the video of the world high jump record being set (2.45m) by Javier Sotomayor. Sotomayor is 1.95m tall. • Think of the following questions after you watch: • What is center of mass? What does this mean? • Where is your body’s center of mass? • The high jump technique to get over the bar is called the Fosbury Flop. Where is the person’s center of mass when they are trying to get over the high jump bar? • Time: 15 minutes

21. Activity 1 • Cut out the shapes from the templates onto construction paper • Draw the shapes in your notebook as well • For shapes A, B, and C, try to locate the object’s center of mass • Where will the object balance on your finger? • Mark the balance points on your sketch in your notebook and on your object • Time: 30 minutes

22. Activity 2 • You will now test to see if your balance point was accurate • Follow steps 3-7 on pp. 28-29 • Record the answers to the questions in your notebook as you go along • Time: 40 minutes

23. Activity 3 • Watch the following videos to determine the athlete’s center of mass • How do you make a football player fall? • What do you notice about the gymnast’s center of mass? • Time: 10 minutes

26. Closing & Homework • Physics to Go, pg. 30, #1, 2, 3, 5

27. Day 4: Defy Gravity • Learning Objectives: • Measure changes in height of the body’s center of mass during a vertical jump • Calculate changes in the gravitational potential energy of the body’s center of mass during a vertical jump • Understand and apply the definition of work • Recognize that work is equivalent to energy • Understand and apply the joule as the unit of work and energy • Apply conservation of work and energy to the analysis of a vertical jump

28. Starter • “No athlete can escape the pull of gravity.” • From previous videos: • Was Michael Jordan able to defy gravity when he went up for his slam dunk? • Was Katarina Witt able to defy gravity while doing a double axel? • Did Javier Sotomayer defy gravity when breaking the world record for high jump? • Did Dominique Dawes defy gravity when she did a double-back in the air? • Explain your answers • Time: 15 minutes

29. Activity 1 • Watch the video of the skater doing a triple axel • You will count the number of frames the skater is in the air • Each frame appears to be “jerky” • Each frame is 1/30 seconds • You will calculate the skater’s “hang time” • Time in air = Number of frames x 1/30 • Watch the video of the basketball player doing a slam dunk • Calculate the basketball player’s “hang time” • Did either athlete “hang” in the air? Explain. • Time: 15 minutes

30. Activity 2 • You will work with your group to analyze a vertical jump • Complete steps 3-8 on pp. 32-34 • Record your data and answers as you go along • 1 answer sheet/group will be handed in at the end of the lesson • Time: 35 minutes

31. Closing & Homework • Read “for you to read”, pp. 35-39 • Read “physics talk”, pp. 40-42 • Physics to go, pp. 43-44, Choose any 6 calculations • Formulas: • Work (J)= Force (N) x distance (m) • Work (J) = Kinetic energy (J) = Potential energy (J) • Potential energy (J) = Mass (kg) x acceleration due to gravity (9.8m/s2) x height (m) • Kinetic energy (J) = ½ x Mass (kg) x velocity2 (m/s)

32. Day 5: Run and Jump • Learning Objectives: • Understand the definition of acceleration • Understand meters per second per second as the unit of acceleration • Use an accelerometer to detect acceleration • Use an accelerometer to make comparisons of acceleration • Distinguish between acceleration and decceleration

33. Starter • Pretend you have met somebody who has never jumped before. • What instructions would you provide to get the person to jump up? • Where do they need to apply force? • What actions do they need to do? • Give instructions to someone in your group to see if they are accurate • Time: 15 minutes

34. Activity 1 • Pg. 45, step 1

35. Activity 2 • Pg. 46, step 2, 3

36. Activity 4 • Pg. 47, step 4-6

37. Closing & Homework • Physics to Go • Pg. 48 #1, 3, 6 • Stretching Exercise • If you have access to an elevator, complete the exercise • If you don’t, watch a clip on Youtube showing what happens to the needle on a bathroom scale when you are in an elevator

38. Day 6: The Mu of the Shoe • Learning Objectives: • Understand and apply the definition of the coefficient of sliding friction, μ • Measure the coefficient of sliding friction between the soles of athletic shoes and a variety of floor surfaces • Calculate the effects of frictional forces on the motion of objects

40. Starter • A shoe store may sell as many as 100 different kinds of sports shoes. • Look at the pictures and explain the difference between the shoes • Why do different sports require different shoes? • What shoes would the sports be used for? • Time: 15 minutes

42. Activity 1 • Follow steps 1-4 on pg. 50-52 • Use any shoe you want, you may want to use 2 different shoes to compare how the soles of the shoe affect how it slides across 2 different surfaces • Surface choices: • Smooth: table, tiles at back of room, lab bench surface • Rough: carpet, grass, cement walkway • For the “filler”, you can use the masses on the back table • Time: 45 minutes

43. Activity 2 • Calculations • Your running shoe has a weight of 3.5N. The shoe slides across a surface when a horizontal force of 12N is applied to it. What is the coefficient of sliding friction? • What do you know? • Force to slide shoe = 12N • Weight of shoe = 3.5N • Solve: • μ = force required to slide object on surface at a constant speed • perpendicular force exerted by the surface of the object • = 3.5N • 12 • = 0.29

44. Closing & homework • You may use this time to work on your chapter challenge • Homework: • Read Physics Talk, pg. 53 • Physics to Go, pg. 54-55 #1, 2, 3, 4, 5 • Assignment, pg. 55 #8

45. Day 7: Concentrating on Collisions (60 mins) • Learning Objectives: • Understand and apply the definition of momentum • Conduct quantitative analysis of the momentum of pairs of objects involved in 1-D collisions • Infer the relative masses of two objects by observing collisions between the objects

46. Starter • In contact sports, very large forces happen during short time intervals. • Name 3 sports where collisions happen, and what the collisions are in the sports • If 2 athletes have a head-on collision, what factors determine which player will make it through the collision? • Time: 15 minutes

47. Activity 1 • Complete steps 1-7 on pp. 56-58 • Balls to use are on the back lab bench • Wood pieces to assemble ramps are on back lab bench • Record observations and answer questions as you go along • Hand in 1/group when completed

48. Closing & Homework • Physics to Go, pg. 59 #1, 2, 3, 6

49. Day 8: Summative Assessment • Presentation of Commentary on Sporting Event