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1. To the MAPs Team's Presentation of: Simple Machines Dr. M. H. Suckley & Mr. P. A. Klozik Email: MAP@ScienceScene.com Visit our Website: http://www.ScienceScene.com (The MAPs Co.)

2. Simple Machines

3. Simple Machines A. Principles of Simple Machines 1. Naïve Ideas/Benchmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Six Simple Machines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3. Why Use Simple Machines? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4. Inclined Plane - Wedges At Work (Wedge & Screw) . . . . . . . . . . . . . . . . 12 a. How Can Changing The Angle Effect Force? . . . . . . . . . . . . . . . . 14 b. Why Take The Longer Road? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 5. Levers a. How Do You Pop The Top? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 b. Examples of the Three Types of Levers . . . . . . . . . . . . . . . . . . . . . 19 6. Pulleys a. How Strong a Force Do You Need? . . . . . . . . . . . . . . . . . . . . . . . . 20 b. Gravity and the Simple Pulley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 c. Which Ways Should You Pull? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 d. Student Pulley System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 e. Paperclip Pulleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 f. Strength of Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7. Wheel and Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8. Which Way Is the Force? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

4. Simple Machines • B. Investigating the Simple Machines • 1. Characteristics of Simple Machines. • a. Work • b. Mechanical Advantage • c. Effort • d. Efficiency • 2. The Simple Machines Workshop (notes) . . . . . . . . . . . . . . . . . 38 • a. Levers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 • b. Pulleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 • c. Inclined Plane / Wedge / Screw . . . . . . . . . . . . . . . . . . . 50 • d. Wheel And Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 • C. Work and Power • 1. Car Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 2. How Much Horsepower Can You Produce? . . . . . . . . . . . . . . 55 • Compound Machines . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 56 • E. The Wake Me Up Machine (a summary) . . . . . . . . . . . . . . . . . 56

5. Simple Machines Summary A. Principles of Simple Machines 1. Six Simple Machines 2. Why Use Simple Machines? 3. Inclined Plane - Wedges At Work 4. Levers 5. Pulleys 6. Wheel and Axle B. Simple Machines 1. The Characteristics of Simple Machines. 2. The Simple Machines Workshop a. Levers b. Pulleys c. Inclined Plane / Wedge / Screw d. Wheel And Axle C. Work and Power 1. Car Power. 2. How Much Horsepower Can You Produce? D. Compound Machines E. The Wake Me Up Machine

7. Thank You! We Had A Great Time

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9. Naive Ideas 1. Simple machine make less work 2. Simple machines always change the direction of the applied force. 3. Work and force have the same meaning and can be used interchangeably. 4. Force X Distance (work) is a way to describe what a machine can do. 5. Simple Machines produce more work than put in. 6. In actual simple machines input work is always equal to output work. 7. Resistive forces found in simple machines can be eliminated withvarious lubricants. 8. Mechanical advantage is larger for big machines and smaller for smallermachines. 9. The efficiency of a machine is an indication of how fast it can do work. 10. Power of a simple machine is an indication of the amount of force that it can apply. 11. Energy changes occur are seldom found when work is done by simple machines. 1 11

10. Objectives/Benchmarks 1. Identify and use simple machines and describe how they change effort. 2, Inclined planes, levers, pulleys, wedges, wheel and axle, force, distance. 3. Manipulate simple mechanical devices and explain how their parts work together. 4. Design strategies for moving objects by application of forces, including the use of simple machines. 5. Analyze pattern of force and motion in the operation of complex machines. 0

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12. Six Simple Machines 0

13. Three things Simple Machines Do • Make Work Easier • Make Work Faster • Change Direction of Force or Effort 2 4

14. Why Use Simple Machines? A machine controls the direction and the motion of force. A machine cannot create energy. A machine can never do more work than the energy put into it. In other words a machine can change the relationship between force and distance (work = F x d) but the total amount of work done is constant. FxD =FxD or FxD=FxD A machine can transform one form of energy such as electrical energy, to another form of energy, such as mechanical energy. 1

15. Why Use Simple Machines? • Pound 2 large nails into scrap lumber. Be sure at least 3 cm of the top-of the nail sticks up above the board. Which moves farther the head of the hammer or your hand? • Try to remove the first nail with your fingers. Were you able to remove the nail? • 3. Use the claw of the hammer to remove the second nail. Was it easier to remove the nail with the hammer? Why? • Turn two wood screws in the piece of scrap lumber. • 5. Try to turn out the first screw with your fingers. Try to remove the second one with the screwdriver. Why do we use a screwdriver to turn the screw? 0 5

16. The Inclined Plane 4

17. The Screw 3

18. The Screw and the Inclined Plane 2

19. The Wedge 1

20. Wedge Examples 0

21. How Can Changing The Angle Affect Force?

22. Why Take The Longer Road?

23. The Lever

24. How Do You "Pop The Top?" • Would it be difficult to remove the lid on a paint can using your fingers? • What can you use to open the can? • What do all these tools have in common? • 4. Which way do you push to open the lid? • 5. What can you observe about the distance traveled by the tip of the tool and the handle?

25. Identifying Types of Levers - FRE 3

26. First Class Second Class Third Class Fulcrum Fulcrum Resistance Effort Resistance Fulcrum Effort Resistance Effort First, Second, and Third Class Levers F R E 2

27. Examples of The Three Types of Levers 3 2 1 2 3 2 3 1 3 1 9

28. Last 0 9

29. The Pulley

30. How Strong A Force Do You Need?

31. Gravity And Simple Pulley Will the elevation of mass A cause it to move when released? "When I let go of these two identical masses what will happen? Write or draw your prediction on paper, but don't say your answer yet. A B

32. Which Way Should You Pull? Machines can change the direction. of a force needed to do work. 1. Record the force readings for each position shown: 2. What does using a pulley to change string direction do the force?

33. Student Pulley System

34. Paperclip Pulleys 1

35. String Paperclip Rubber Band 0

36. Fulcrum Strength Of Forces

37. The Wheel and Axle 2 1

38. Wheel and Axle Counterbalance Brace and Bit Screwdriver The Wheel and Axle - Examples 1

39. Wheel and Axle – Croquet Mallet Wheel Axle 0

40. Which Way Is The Force?

41. Simple Machine Terms Work Output WO = Resistance x Distance The Resistance Moved WO = R x DR Work Input WI = Effort X Distance The Effort Moved WI = E x DE 1

42. Simple Machine Terms This relationship between input force and distance can vary as long as the equality is maintained by varying the output force and distance. Effort(Work input)=Resistance (Work output) (F x D)=(F x D) FxD=FxD FxD=FxD 0 2

43. Simple Machine Terms Actual Mechanical Advantage AMA = Resistance (R) / Effort (E) Ideal Mechanical Advantage IMA = Distance effort moved / Distance resistance moved

44. Simple Machine Terms Ideal Effort IE = Resistance / IMA Actual Effort Measured

45. Simple Machine Terms Efficiency %E = (Work Output / Work Input) X 100

46. Notes on the Simple Machine Device The Resistance exerts a force of 0.32-n Each Effort/Washer exerts a force of 0.08-n Small washers exert a force of 0.016-n A free hanging pulley will act as an additional resistance or force. To compensate setup the pulley system without the resistance and zero out the system by adding enough washers to balance the system. Then add the resistance and add enough washers to balance the system. The additional washers represents the force of the resistance. 1 2

47. E E R R Why can placement distance be used as Effort or Resistance Distance? The Resistance Placement is 6 and the Effort Placement is 3 Then If the effort, or resistance, was moved to the extreme, perpendicular, then the distance moved would equal the Placement distance. Therefore: If Effort Placement is 3 then Effort Distance = 3 If Resistance Placement is 6 then Resistance Distance = 6 0 4 Effort Placement = 3 Resistance Placement = 6

48. Simple Machines Workshop - Levers First Class LeverSecond Class LeverThird Class Lever 7

49. Effort Distance Resistance Distance Effort Resistance Simple Machines Workshop – First Class Lever 1

50. First Class Lever - Data Trial 1 Trial 2 Trial 3 Trial 4 1. Distance (meters) a. Resistance Placement 0.0900 0.0600 0.0300 0.0900 b. Resistance Distance DR 0.0900 0.0600 0.0300 0.0900 c. Effort Placement 0.0900 0.1200 0.1200 0.1200 d. Effort Distance DE 0.0900 0.1200 0.1200 0.1200 2. Force (Newton’s) a. Resistance R 0.32-n 0.32-n 0.32-n 0.32-n b. Effort E  0.32-n 4.0-w 0.16-n 2.0-w 0.08-n 1.0-w 0.24-n 3.0-w 3. Work Input (joules) WI = E x DE 0.0288 0.0192 0.0096 0.0288 4. Work Output (joules) WO = R x DR 0.0288 0.0192 0.0096 0.0288 5. % EFFICIENCY %E = (WO/ WI ) x 100 100 100 100 100 6. Ideal Mechanical Advantage IMA = DE / DR 1 2 4 1.33 7. Ideal Effort (Newton) IE = R / IMA 0.32 0.16 0.08 0.24 8. Actual Mechanical Advantage AMA = R /E 1 2 4 1.33 29 0