colorado/physics/phys1110/phys1110_fa07/mainPage3.html

1. Concept Presentation Projectile Motion Presenter: Nate Mohanlall 22nd July 2010 Mentor: Sean Henderson http://www.colorado.edu/physics/phys1110/phys1110_fa07/mainPage3.html

2. Overview Curriculum Placement/Expectations Lesson Sequence/Teaching Ideas Projectile Motion Misconceptions / Concepts Strategies for solving problems Applications and Societal Implications Assessment and Evaluation

3. Curriculum Placement: BIG IDEAS Grade 2 : Structures investigate and describe different kinds of movement (e.g., by observing how toys andother everyday objects move) identify ways in which the position of an object can be changed (e.g., by pushing, bypulling, by dropping) Grade 11 Physics: Kinematics Motion involves a change in the position of an object over time. Motion can be described using mathematical relationships. Many technologies that apply concepts related to kinematics have societal and environmental implications. Grade 12 Physics: Dynamics Forces affect motion in predictable and quantifiable ways. Forces acting on an object will determine the motion of that object. Many technologies that utilize the principles of dynamics have societal and environmental implications.

4. A1. Scientific Investigation Skills • A1.5 conduct inquiries, controlling relevant variables, adapting or extending procedures as required, and using appropriate materials and equipment safely, accurately, and effectively, to collect observations and data • A1.10 draw conclusions based on inquiry results and research findings, and justify their conclusions with reference to scientific knowledge • A1.12 use appropriate numeric (e.g., SI and imperial units), symbolic, and graphic modes • of representation (e.g., vector diagrams, free-body diagrams, vector components, and Algebraic equations)

5. B2. Developing Skills of Investigation and Communication B2.1 use appropriate terminology related to dynamics, including, but not limited to: inertial and non-inertial frames of reference, components, centripetal, period, frequency, static friction, and kinetic friction [C] B2.2 solve problems related to motion, including projectile and relative motion, by adding and subtracting two-dimensional vector quantities, using vector diagrams, vector components, and algebraic methods [PR, AI, C]

6. C1. Relating Science to Technology, Society, and the Environment B1.1 analyse a technological device that applies the principles of linear or circular motion (e.g., a slingshot, a rocket launcher, a race car, a trebuchet) [AI, C] B1.2 assess the impact on society and the environment of technological devices that use linear or circular motion (e.g., projectile weapons, centrifuges, elevators) [AI, C]

7. Lesson SequenceDay 1

8. Class Activity What type of motion is the marble experiencing vertically? What type of motion is the marble experiencing horizontally? http://media.ehs.uen.org/html/PhysicsQ2/Horizontal_Projectiles_03/ramp.jpg

9. Graphic Organizer

10. What do the following situations have in common? A truck is equipped with a flare launcher which is capable of launching a sphere vertically (relative to the truck). A relief package drops from a low-flying airplane.

11. Suppose a truck is equipped with a flare launcher which is capable of launching a sphere vertically (relative to the truck). If the truck is in motion and launches the flare and maintains a constant horizontal velocity after the launch, then where will the flare land (neglect air resistance)?a. in front of the truck b. behind the truck c. in the truck

12. http://www.physicsclassroom.com/mmedia/vectors/tb.cfm

13. 2. Suppose a rescue airplane drops a relief package while it is moving with a constant horizontal speed at an elevated height. Assuming that air resistance is negligible, where will the relief package land relative to the plane? a. below the plane and behind it. b. directly below the plane c. below the plane and ahead of it

14. http://www.physicsclassroom.com/mmedia/vectors/pap.cfm

15. Lesson sequenceDay 2 and 3

16. Lesson sequenceDay 4

17. Concept Circle Modify the strategy by: leaving one section empty, to be filled by students; including one non-example and asking students to find which item does not belong and to justify their answer. Concept:____________

18. Physics Toolbox

19. Differentiating Physics InstructionParallel Questions

20. Misconception # 1 Students develop personal “theories of motion” by generalising the ideas they acquire from observation of objects in everyday situations (Keeports, 2000) Heavier objects fall faster.

21. Addressing Misconception # 1 Animation are useful tools for visual learners. Here we see that heavier objects hit the ground at the same time as lighter ones. http://library.thinkquest.org/2779/

22. Misconception # 2 If one object is dropped from a specific point and another is projected forward from the same point, then the projected object will take longer to reach the ground.

23. Let’s Consider… Ball A falls freely from a specific height and at the same time ball B is thrown horizontally from the same height. (a) How do we compare the acceleration of the two balls. (b) Which ball will hit the ground first? Why? Nelson: Physics 12 p.41

24. Addressing Misconception # 2 This animation shows that both objects reach the ground at the same time. this illustrates the concept in a different way for Visual learners Nelson: Physics 12 p.41 http://library.thinkquest.org/2779/

25. Misconception # 3 Parabolic Motion Showing the parabolic nature of projectiles leads the student to believe they are quite different from linear falling or horizontal motion

26. Addressing Misconception # 3 An easy way to deal with this is to plot the motion of a freely falling object and a horizontally moving object on the same graph. When the intersection points at the same time, are connected, the result is a parabola.

27. Addressing Misconception # 3 The green ball illustrates uniform motion The red ball illustrates free fall and uniform accelerated motion The combination of these two motions at equal time intervals yields the parabolic path shown by the blue ball! Horizontal and vertical motion are independent of each other http://www.physicsclassroom.com/mmedia/vectors/bds.gif

28. Misconception # 4 Parabolic Motion At the top (peak) of its trajectory, the velocity of a projectile is always momentarily zero. The acceleration of the object is also zero, at the peak.

29. Let’s Consider A basketball ball is thrown at an angle from one person to another. What is the velocity of the object at the peak of the flight? What is the acceleration of the object at the peak of the flight?

30. Addressing Misconceptions # 4 Have students look at the horizontal and vertical velocity vectors throughout parabolic flight. Demonstrate that the velocity is not zero as there must be some horizontal motion still (it doesn’t stop in midair).

31. # 4 Cont’d If you throw an object in the air, it stops briefly (vertical velocity is zero) but acceleration is not zero (gravity doesn’t stop). What is its role? To change the direction of the velocity vector. http://www.physicsclassroom.com/Class/vectors/U3L2c.cfm

32. Misconception # 5 Students believe that the greater the angle of projection, the greater the horizontal distance travelled by a projectile. Class Activity Nelson Physics 12: Comparing Horizontal Range p.49 Use formula to verify

33. Can you spot the Mistake in this animation? http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm

34. Strategies for solving problems • Frame the Problem • Identify the Goal • Variables and Constants • Involved in the problem • Known • Implied • Unknown • Strategy • Calculations • Validate McGraw-Hill Ryerson Physics 11

35. Applications and Societal Implications Sports Projectile Weapons Forensic Forest Fire Circus/fireworks Drop food in disaster areas

36. Assessment and Evaluation Assignment Quiz Test Lab

37. Monkey and Banana Problem

38. Monkey and BananaThrow at the Monkey in a Gravity Free Environment http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm

39. Throw above the Monkey with Gravity On http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm

40. Throw at the Monkey at a Fast Speed with Gravity On http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm

41. Throw at the Monkey at a Slow Speed with Gravity On http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm

42. References http://www.lon-capa.org/~mmp/kap3/cd060.htm http://www.walter-fendt.de/ph14e/projectile.htm http://www.falstad.com/mathphysics.html http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm Keeports, D. (2000). Addressing physical intuition-a first day event. The Physics Teacher,38, 318-319.