Bernoulli’s Principle

Natalie O’NealVickie RinconesEmily Perkins

Brittany SchultzTenneille Duke

Introduction

• Subject: Science

• Objective: To discover Bernoulli’s Principle

• Materials: Hair dryer, ping pong balls, balloons, straws, and coke cans

• Methods: Notes and experiments

• Grade: 8th grade

• Age: 13 & 14 year olds

• Languages: 2 - English and Spanish

Strategies

• Sheltered Instruction• Scaffolding by repetition of vocabulary • Cooperative learning by working in groups

• Students learn through:Kinesthetics by performing experimentsAuditory learning by listening to lectureVisual learning by seeing realia and

watching video

Bernoulli’s Principle

• What are we learning today? – Bernoulli’s Principle

• Why are we learning about it?– To understand pressure systems and apply

them to real life examples

• How are we going to learn?– We will learn through note-taking and hands-

on experiments.

• What should we know before we begin?– Key Terms: Speed, Velocity

Who is Bernoulli?

• 18th century Swiss scientist

• Studied fluid flow in pipes

*Fluid = any liquid

Vocabulary

• Speed = Rapidez - how fast something moves

Formula: Distance / Time

• Velocity = Velocidad – speed of an object and its direction of motion

• Air Pressure = Presión de Atmosférica – the force exerted by air on any surface in contact with it

• Lift = Ascender – raise from a lower position to a higher position

*Exerted = pushed

Bernoulli’s Principle

• Textbook Definition: When the speed of a fluid increases, internal pressure in the fluid decreases.

• Our Definition: When speed increases, pressure decreases.

*Increase = to go higher*Pressure = a type of force*Decrease = to go lower

High Pressure/Low Pressure

• High Pressure always travels to Low Pressure areas.

Experiments

• Video Link: http://www.youtube.com/watch?v=ctJyu5ete6Y

• Hair dryer demonstration• Coke can demonstration

Additional Examples• 1. Umbrella

– The curved part of an umbrella causes air moving across it to have a higher velocity (similar to an airplane’s wing).

– On a windy day, the higher velocity creates much lower pressure on the top of the umbrella.

– The high pressure under the umbrella pushes up to the lower pressure, causing the umbrella to turn inside out.

Additional Examples

• 2. Faucet and ball – The moving water creates low pressure

because of the increased velocity. – The high pressure around the stream

pushes the ball towards the low pressure, causing it to touch the water stream.

Additional Examples

• 3. Perfume Sprayer – When you squeeze the bulb, air rushes

across the open end of the tube to create low pressure.

– Higher pressure on the liquid pushes it up and it is carried away by the stream of air.

Additional Examples

• 4. Insects – Insects increase their lift by flapping

their wings forward and backward, not up and down.

– The tilt of their wings provide an angle to create low pressure and lift.

Additional Examples

• 5. Shower curtain – When taking a shower, the moving

water creates low pressure inside the shower.

– High pressure outside the shower moves towards the low pressure, causing the shower curtain to swing against your legs.