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Chapter1: principles of Design

Chapter1: principles of Design. Engineering Design and Problem Solving. Introduction/Description.

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Chapter1: principles of Design

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  1. Chapter1: principles of Design Engineering Design and Problem Solving

  2. Introduction/Description The Intro-Mini Project will introduce the engineering design process through a problem solving scenario, as well as the concept of Coefficient of Restitution (COR), and sketching and technical drawing. You will work in project teams and present your data and solutions to the class.

  3. Chapter 1: Outline Engineering Careers History of Engineering and Innovation Importance of Innovation Future Challenges of Innovation

  4. Objectives and Results Objectives • To review scientific concepts of kinetic energy, potential energy, and energy transfer. • To determine the coefficient of restitution (COR) for various sports balls. • To understand elastic and inelastic collisions. • To practice sketching and creating technical drawings of various sports balls using graphic tools. • To apply the concept of engineering design to a problem scenario. • To reinforce collaborative and communication skills.

  5. Objectives and Results, cont. Results • Students will be able to explain the concept of engineering design. • Apply engineering design concepts to a problem scenario. • Practice sketching technical drawings and engineering notebooks. • Reinforce collaborative and communication skills.

  6. Schedule of Assignments

  7. Vocabulary • Coefficient of Restitution • Elastic Collision • Energy Transfer • Inelastic Collision • Kinetic Energy • Potential Energy

  8. Team Building What is a team? “A team is a small group of people with complementary skills who are committed to a common purpose, performance goals, and approach for which they hold themselves mutually accountable.” Katzenbach, Jon R., and Smith, Douglas K., The wisdom of teams: creating the high-performance organization; Jon R. Katzenbach, Douglas K. Smith Harvard Business School Press, Boston, Mass.: 1993

  9. What is Team Building? Creating a successful team can be a challenging task. Teams must rely on the process called team building. Team building integrates individual skills and resources into a unified effort.

  10. Team Building Actions Team building involves the following actions: Encouraging team members to examine how they currently work together Portraying ideal ways of collaborating Exploring the gaps and weaknesses they currently suffer from Establishing action plans for implementing more effective ways of cooperating

  11. What is a Team Leader? • Team building is best aided by a team leader or a facilitator. • A team leader or facilitator performs several tasks: • Helps the group learn about itself • Observes team meetings • Gives feedback and key observations to the team

  12. What Does a Team Leader Do? A team leader probes, questions, listens, watches for nonverbal cues, and stimulates problem solving. The intended results include a team that is open to new alternatives, who is aware of their resources, has the ability to think and act independently, and is willing to explore the consequences of their current or proposed actions.

  13. Benefits of Team Building There are several benefits for executing team building: Improves morale and leadership skills Clearly defines objectives and goals Improves processes and procedures Improves team productivity Identifies a team's strengths and weaknesses Improves the team’s ability to problem solve

  14. Team Building Assignment In your team, discuss leadership roles and responsibilities of team members. Select roles for each team member. Write and agree to team contract. Have your teacher approve your team contract. Discuss implications of team building in the field of engineering.

  15. Energy • Energy Transfer – moving energy from one body to another • Kinetic Energy - energy that a body possesses by virtue of being in motion • Potential Energy - energy which an object has because of its position

  16. Loss of Energy • Mechanical energy is the sum of the energy of motion: • KE (Kinetic Energy) = ½ mv2 • GPE (Gravitational Potential Energy) = mpg where m = mass, v = velocity (speed), g = gravitational pull, and p = potential energy. • The total energy in a system is conserved, but when a ball bounces, it loses mechanical energy because the collision between the ball and the surface is inelastic.

  17. Coefficient of Restitution • The coefficient of restitution (COR), or bounciness of an object, is a fractional value representing the ratio of velocities after and before an impact (vup/vdown). • An object with a COR • =1 collides elastically. • < 1 collides inelastically.

  18. Elastic and Inelastic Collision • Elastic Collision - an encounter between two bodies in which the total kinetic energy of the two bodies after the encounter is equal to their total kinetic energy before the encounter. • Inelastic Collision - a collision in which kinetic energy is not conserved

  19. Determining Coefficient of Restitution The amount of energy that the ball loses will depend on the coefficient of restitution (COR), a ratio of its pre-collision velocity (vup) to its post-collision velocity (vdown). Coefficients of Restitution YouTube video

  20. Using the Velocity Formula • In order to find velocity (v), use the height of the ball after it hits the ground (h) and put it in the following equation: v = √(2gh) where v = velocity, g = 9.8m/s2, and h = height when ball is dropped. • Coefficient of Restitution = √(2gh)) / √(2gH) = √(h/H) where H is the initial height of the ball.

  21. Ball Bounce Article • “The dynamics of a collision between a ball and another object can be determined in principle, from the individual conditions and the functional form of the force acting on the ball.” Ball Bounce Experiment • Dynamics of Bounce • Experimental Techniques and Results • Comparison of Static and Dynamic Hysteresis Curves • Ball Variations • Effects of Ball Speed

  22. Student Scenario • It’s the beginning of the school year. Students are interested in joining an extracurricular sporting team. There are several female and male sporting teams to choose from at the high school. • What are the sporting teams at your high school? • Research and list the various types of extracurricular sporting teams available for both female and male students. • Gather the types of balls used for each extracurricular sporting team.

  23. Student Project Basics Individually and in teams, you will • calculate the coefficient of restitution (COR) for at least 5 sports balls, • create sketches and diagrams in your engineering notebook for each ball, • design a new type of ball for at least one sport, • document the design process your team went through, and • present your findings to the class.

  24. Step 1: Getting Started • Determine the female and male sporting teams on campus. • Gather the types of sports balls used by each female and male sporting team on campus and document them in your engineering notebooks.

  25. Step 2: Collecting Data Gather a • meter stick, • balance (to explore relationship between mass and energy for extension applications), and • random measurement equipment (figure out what you really need to use), timers, graduated cylinders, balances, forces, scales, etc.

  26. Step 3: Analysis • Sketch designs of the various sports balls on graph paper. • Create technical drawings of the various sports balls using software graphic tools. • Demonstrate teamwork and professionalism. • Determine the height of the ball after it bounces. • Determine the coefficient of restitution (COR) of the sports balls.

  27. Step 4: Engineering Design • Considering your data and what you learned about the behavior of each ball, would any of the balls perform better in another sport? Explain. • Design a new type of ball for at least one sport. There is not necessarily a right or wrong answer. • Create a presentation about the coefficient of restitution of the various sports balls and the new type of ball you are proposing for at least one sport. Be sure to document your procedure, data collected, and conclusions drawn.

  28. Step 5: Presentation Prepare a Microsoft PowerPoint team presentation of your work (rationale and results). • Reflect on the concepts of energy and collisions. • Explain what you have learned and why different balls might be used for different sports. • Describe the new type of ball your team designed for at least one sport. • In as much detail as possible, explain the steps of the process your team went through in order to come up with the new ball design.

  29. Conclusion/Questions to Consider • Why is the coefficient of restitution of a ball so important in sports? • What are the factors that determine the COR? • What might happen if you tried to use the “wrong” ball for a sport?

  30. Credits • ClipArt; http://www.clipart.com/en/ • Images; http://commons.wikimedia.org/wiki/Main_Page • Slide 19 Coefficient of Restitution video; from YouTube user; Gaby Salguero http://www.youtube.com/watch?v=0bis1cA842c

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