Example of Use of Multiple Demonstrations and/or Hands on Activities: Bernoulli s Principle

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1 Example of Use of Multiple Demonstrations and/or Hands on Activities: Bernoulli s Prciple Michael R. Vitale Center for School Development, Inc. Nancy R. Romance Region V Area Center for Educational Enhancement, Florida Atlantic University

2 Bernoulli s Prciple Bernoulli s prciple states that where the velocity of a fluid is high, the pressure is low, and where the velocity is low, the pressure is high. Pressure is defed as force per unit area where the force F is understood to be actg perpendicular to surface area A. It is an experimental fact that fluid exerts a pressure all directions. At a particular pot of a fluid at rest, the pressure is the same all directions.

3 Considerg Vocabulary from Bernoulli Text (Note- these terms are all used explag the followg hands-on experiments) Prciple Force Velocity Per Unit Area Fluid Perpendicular Pressure Experimental Fact

4 Bernoulli Demonstration Example 1 (Demonstration and/or Hands- On + Explanation of Why Paper Strip Rises) blow air over top of paper paper strip

5 Bernoulli Demonstration Example 2 (Demonstration and/or Hands- On + Explanation of Why Tent Collapses) paper folded to tent blow air through tent

6 Bernoulli Demonstration Example 3 (Demonstration and/or Hands- On + Explanation of Why Cans Fall Together) empty cans blow air between cans straws

7 Bernoulli Propositional Concept Map (Representation of Bernoulli s Prciple + Referenced to Prior Examples) Bernoulli's Prciple Concept Map of Bernoulli's Prciple v olv es relationships among can be def ed as Flowg Substances clude Liquids Fluids must travel contuous Gases can hav e v olv es Direction and v olv es Velocity Speed of a f luid can be af f ects Rest- No Speed or High Speed or Low Speed results results results Pressure can be Same Pressure or Low Pressure or High Pressure results results results results Force can be Same Force or Less Force or More f orce acts can be thought of as Push or Pull that acts Perpendicular to Surf ace

8 Bernoulli Demonstration Example 4 (Demonstration and/or Hands- On + Explanation of Why Cans Fall Together) pg-pong ball blow air to straw this direction straw

9 Bernoulli Demonstration Example 4 (Prediction of Outcome Prior to Demonstration and/or Hands-On: Confirmg Ball Does Not Fall Out of Funnel) blow air to funnel pg-pong ball funnel

10 Bernoulli Demonstration Example 5 (Prediction of Outcome Prior to Demonstration and/or Hands-On: Confirmg Ball Jumps from One Glass to the Other) blow air this direction to glass pg-pong ball

11 Bernoulli s Prciple- Generalization to Expla Lift of Airplane Wgs Airplane Wg (Arrows dicate airflow) Air Wg Direction of Airplane

12 Bernoulli Propositional Concept Map (Representation of Bernoulli s Prciple Applied to Lift of Airplane Wgs) Bernoulli's Prciple Applied to Airplane Wg Lift Concept Map of Bernoulli's Prciple Applied to Airplane Wgs v olv es relationships among that is a can be def ed as Flowg Substances Air as a Fluid trav els contuously with Gas v olv es Direction can hav e and v olv es Speed Velocity ov er wg surf ace is af f ects Higher Speed ov er the curv ed top surf ace and Lower Speed under the bottom wg surf ace resultg resultg Pressure is Lower Pressure on the top of the wg combation with Higher Pressure under the wg results resultg resultg Force is Less Force on top of wg are opposg f orces More Force under the wg causes can be thought of as Push (or Pull) that acts on wg to hav e upward lif t

13 Implications of Hands-On Sequence Teachg for Understandg Pots to Note About Bernoulli Demonstrations Role of conceptual knowledge understandg and application How conceptual knowledge provides the means for relatg different events (i.e., the series of different activities and the extension to airplane wgs) How, without conceptual knowledge, the activities would have been done rote fashion by simply dog the experiments and literally describg what happened

14 Usg Organization of Knowledge Concept Map as a Key for Writg Writg Assessment Assignment Instructions: Use the Bernoulli Concept Map as a Guide to develop a multi-paragraph passage: How airplanes are able to fly. Scorg assumptions for writg task: Focus -- how clearly the idea or theme is presented or mataed Organization -- how the logical development of the supportg ideas to the ma idea are developed throughout the paragraph Support -- the quality of details used to expla, clarify, or defe Conventions -- appropriate grammar usage Note- How the concept map would be useful writg. How the writg task would be approached with vs. without the Concept Map.

15 Bernoulli s Prciple Revisited (Now Understandable Terms of Hands-On + Explanations Usg Bernoulli Terms) Bernoulli s prciple states that where the velocity of a fluid is high, the pressure is low, and where the velocity is low, the pressure is high. Pressure is defed as force per unit area where the force F is understood to be actg perpendicular to surface area A. It is an experimental fact that fluid exerts a pressure all directions. At a particular pot of a fluid at rest, the pressure is the same all directions.

16 Possible Test of Student Understandg of Bernoulli s Prciple 1 Accordg to Bernoulli s Prciple, what happens to the pressure of a fluid when velocity changes from high to low? 2 Accordg to Bernoulli s Prciple, fluid at rest exerts pressure that is: a. low b. high c. equal all directions 3 Accordg to Bernoulli s Prciple, what factors fluence the amount of pressure on a surface exerted by a fluid? 4 Use Bernoulli s Prciple to expla how a steeply sloped roof might be affected by hurricane force wds. 5 Suppose you were buildg a race car. How could you use Bernoulli s Prciple to design wgs for your car that would help it hold the road at high speed?