LIVE INTERACTIVE LEARNING @ YOUR DESKTOP
June 4, 2012
NES: Engineering Design Challenge: Forces and Motion –
The Great Boomerang Challenge
Presented by: Rudo Kashiri
Engineering Design Challenge:Forces and Motion
The Great Boomerang Challenge
Rudo Kashiri
NES Education SpecialistNASA Langley Research Center
AgendaLesson overview
NASA connection
STEM connection
Extensions & resources
NASA Explorer Schools
IntroductionGrade Level: 9 through 12
Subject Areas: Science and Engineering
National Education Standards
‐ Physical Science: Forces and Motion
‐ Science and TechnologyAbilities of technological designUnderstanding about science and technology
Prep Time: 30 minutes
Class Time: Three 50‐minute periods
Learning Objectives
Use the engineering design process to complete a team challenge
Show how aerodynamic forces influence the flight characteristics of designs‐ including Bernoulli’s Principle
Lesson Support
Boomerangs were once used as weapons.
Poll Question
✔ True
✖ False
Let’s Pause forQuestions.
Lesson in Detail
Boomerang Design Challenge:
Design and construct a returning boomerang that will allow for the greatest flight distance relative to the accuracy of boomerang return.
Materials
Sheets of craft foam
Engage
Explore
Explain
Extend
Evaluate
5‐E Inquiry Lesson Design
Engage
Gain attention, recall prior knowledge, and introduce the learning objectives/problem
Explore
Design, build, and test a model boomerang
Throwing the boomerang
Measure
DesignDesign
BuildBuild
TestTestRecordDataRecordData
AnalyzeResultsAnalyzeResults Engineering
Design ProcessEngineering
Design Process
Design Factors
• Mass• Number of blades• Blade length• Blade thickness• Camber• Left‐handed vs. right‐handed• Angle of attack
Let’s Pause forQuestions.
Explain
Discuss the aerodynamic forces and allow students to explain reasons for their designs
Will a boomerang work in microgravity?
✔ Yes
✖ No
Poll Question
Extend
Discuss principles of boomerang flight on Earth vs. aboard ISS
Evaluate
Use Evaluation Rubric‐Design Packet to assess student learning
Let’s Pause forQuestions.
NASA Connection
Aerodynamics research
Engineering studies
Computer simulation technology
NASA low‐speed airfoil research
X‐48 Experimental Aircraft
Set airfoil angle at 0.0 degrees
Push Velocity, Animation, and Close View buttons
Move the probe to “A” ‐What is the velocity?
Move the probe to “B” ‐What is the velocity?
Experiment #1
How does velocity of A compare to B?
Airfoil angle: 4.5 degrees Change angle to 4.5 degrees‐What is the value of lift?
What is the velocity on the upper and lower surface of the foil?‐Which surface has higher velocity?
Push the Pressure button‐Which surface has higher pressure?
How does this relate to the velocity?
Which surface has higher velocity?
Which surface has higher pressure?
Bernoulli's Principle
How is a boomerang like an airplane?
Which of the following can be used to describe the flight of a boomerang?
Aerodynamic lift
Newton’s 2ndlaw of motion
CentripetalforceGyroscopic precession
Moment of inertia
How does a boomerang work?
Wings produce lift
The boomerang moves forward and spins, creating uneven lift
The spinning produces gyroscopic stability
Sample Physics Question
What happens to Angular Momentum (L)if the Angular Velocity (ω) is left constant while the Moment of Inertia (I) increases?
Angular Momentum (L) = Moment of Inertia (I) multiplied by Angular Velocity (ω)
Using Newton’s second law of motion: F = mato calculate p, momentum
F = mama = dp/dtF = dp/dtp = m v
To calculate Torque is the rate of change of angular momentum, dL/dt.
Calculations Examples
Let’s Pause forQuestions.
Lift Misconception
Equal transit time:
Incorrect airplane wing explanation
1. Push Direction button and change the angle to 4.5
2. Move the yellow particle at both A and B to the rear of the airfoil
3. Do the particles line up far downstream from the airfoil?
Experiment #2 1. Push Direction button2. Change the angle to a
positive number
Use the slider to move the yellow particle to the rear of the airfoil
Do the particles line up far downstream from the airfoil?
Particles do not line up far downstream from the airfoil
Incorrect airplane wing explanation
Let’s Pause forQuestions.
http://explorerschools.nasa.gov
Video Collection
http://explorerschools.nasa.gov
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