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Science & Engineering How Is Engineering Different from Science ?. “Scientists study the world as it is; engineers create the world that never has been.” -Theodore von Kármán NASA / JPL Aerospace Engineer.
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Science & Engineering How Is Engineering Different from Science? “Scientists study the world as it is; engineers create the world that never has been.” -Theodore von Kármán NASA / JPL Aerospace Engineer
Engineering Design Challenge:Spaghetti TowerTo construct a tower as high as possible using spaghetti and marshmallows. ...There are many ways of building towers using spaghetti and marshmallows. Materials: 20 pieces of dry spaghetti 30 mini marshmellows Scissors (to cut spaghetti) Ruler Meter Stick for measuring height
Scientific Method The steps : Ask a Question Do Background Research Construct a Hypothesis Test Your Hypothesis by Doing an Experiment Analyze Your Data and Draw a Conclusion Communicate Your Results
Question: Do you think a wide base or a narrow base will result in a taller tower?
Hypothesis: If I build a wide base, then I will have a taller tower.
Independent Variables: • (What I can control) • 2-D Geometric Shapes • Triangle • Square • Circle (Polygon) • 3-D Geometric Shapes • Pyramid • Cube • Cylinder or Sphere Dependent Variable: (Beats me I don’t know) Height Identification of Variables
Select One Independent Variable Squares and Cubes of fixed sizes Prove or disprove the hypothesis You may or may not have built the tallest tower Gain Scientific Knowledge
Engineering Design Process A series of steps that lead to the development of a new product or system. STEP 1: Identify the Problem STEP 2: Brainstorm ( generate ideas & possible solutions) STEP 3: Design (explore possibilities & select an approach) STEP 4: Build (Model or Prototype) STEP 5: Test STEP 6: Redesign (Refine the design) STEP 7: Share Solutions
No Single “Correct" Solution or Approach • “EXPLORER" METHOD • Typically used for new design ideas or research. • It is useful in initial design and specification stages, • and is often used when in "unfamiliar territory“ • Move in some direction • Look at what you find there • Record what you find in your notebook • Analyze findings in terms of where you want to be • Use results of analysis to choose next direction • Back to 1 and continue exploring
Summary A Scientist asks a question and develops an experiment, or set of experiments, to answer that question. An Engineer uses the engineering design process to create new solutions to problems Both gain scientific knowledge
Design the Tallest Freestanding Spaghetti Tower • Materials : • 20 strands of uncooked spaghetti • 1 m. masking tape • 1 m. kite string • Scissors • Ruler • Meter Stick • 12 “ square of cardboard (build & move tower) • Option: Substitute 30 mini-marshmallows for 1 m. of masking tape
Properties of Dry Strand of Spaghetti and Mini-Marshmellow Tension Force Compression Force Marshmallows handle compression Spaghetti cannot hold much compression; therefore, its breaks very easily • Marshmallows do not hold up to tension • Spaghetti cannot hold much tension; therefore, it breaks very easily
Problem Solving Tension Force Compression Force Strategy – Fresh marshmallows are more sticky and grip spaghetti Strategy – Double up the spaghetti strands (two strands side by side) for extra strength, especially at the foundation Strategy – Push spaghetti deep into marshmallow Strategy – Use marshmallows side by side for extra strength and use small pieces of spaghetti to pin marshmallows
Properties of String Tension Force Compression Force String handles tension String does not handle compression
Design The Tallest Spaghetti Tower That Can Withstand A Load Materials : Uncooked spaghetti 1 m. masking tape 1 m. kite string On large marshmallow placed on top (load) Scissors Ruler 12” piece of cardboard (build & move tower) Option: Substitute 30 mini-marshmallows for 1 m. masking tape
Design the Tallest Spaghetti Tower That Can Withstand The Largest Load Option: • Which Spaghetti Tower has the best Structure Effectiveness • Structure Effectiveness = (maximum weight structure can hold) / (weight of structure alone) • Weight tower structure • Place a 3x5 file card on top of Tower and add units of mass (washers or pennies) until structural failure
Design the Tallest Earthquake Proof Spaghetti Tower Build a simple, non-motorized earthquake “shake” table Allow movement in 6 directions: Back-and forth side to side, and up-and-down To survive an earthquake test, the building must not collapse for 10 seconds after the earthquake begins.
Design The Tallest Earthquake Proof Spaghetti Tower Challenge • Materials : • 20 strands of uncooked spaghetti • 1 m. masking tape • 1 m. kite string • Scissors • Ruler • Meter Stick • 12” square of cardboard (build & move tower) • Earthquake “Shake” Table • Option: Substitute 30 mini-marshmallows • for 1 m. of masking tape
Types Of Waves Longitudinal Wave Traverse Wave
WAVE A disturbance that travels through a medium, transporting energy from one location (its source) to another location without transporting matter. Particles of the medium move in a direction perpendicular to the wave motion direction Particles of the medium move in a direction parallel to the wave motion direction
Simple Non-Motorized Shake Table • Materials: • Piece of board or plywood into a 12” square • 2” x 4” Frame that fits around the wood square with around 1/2” clearance between the outer edge of the square and the inside edge of the frame • Eight Wood Screws • Eight Rubber bands (32 or 64)
Assembly: Mount 2 wood screws on the under side each side of the plywood with ¼” sticking up Mount wood screws on the top edge of each side of the frame with ¼ “ sticking up Loop a rubber band around each pair of screws so that the plywood square is suspended like a trampoline within the frame Option: Motorize the Shake Table Attach a cell phone underneath the plywood, set to vibrate (vibration motor); then call phone
Modified Saffir - Simpson Scale(Math Scale x 30 increase in Energy)
Design The Tallest Hurricane Proof Spaghetti Tower Materials : • 20 strands of uncooked spaghetti • 1 m. masking tape • 1 m. kite string • Scissors • Ruler • Meter Stick • Three speed Box Fan • 12” square of cardboard (build & move tower) Option: Substitute 30 mini-marshmallows for 1 m. of masking tape