Learning Objective: 3.6 Understanding Bernoulli’s PrincipleMethod: Mastery LearningApproach: Effective Questioning Sequence and Inquiry

Activity 1: State Bernoulli’s Principle

1. Three activity stations are prepared in lab.

2. Students are asked to perform the 3 activities below in groups.

Station 1: Blow above a strip of paper

Station 2: Blow through a straw between 2 ping pong balls.

Station 3: Air is blown between 2 empty cans

3. Students are asked to write their report for each activity based on the questions below:

3.1 What do you observe when you blow the air slowly?

3.2 What do you observe when you blow the air faster?

3.3 What causes the difference between the situations that have been observed? 3.4 What is the relationship between velocity of the moving air and its pressure?

(Teacher state the Bernoulli’s Principle)

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Activity 2: Explain that a resultant force exists due to a difference in fluid Pressure

1. Based on the previous observations, students are asked to:

a. compare the air pressure at X and Y.

b. name the physical quantity that is produced due to the pressure difference between X and Y .

c. state the relationship between the pressure difference and the force produced.

2. Teacher guides students to understand the Bernoulli’s principle.

3. Students are asked to state any applications/natural phenomena related to the Bernoulli’s principle.(Aerofoil/ Bunsen burner/ Carburetor/ Insecticide sprayer)

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Activity 3 : Applications of Bernoulli’s principle

1. To demonstrate that the aerofoil can produce a lift force.

1.1 Cut out an aerofoil from polystyrene

1.2 Make a hole in the middle of the aerofoil so that it can be slotted onto a retort stand

1.3 Use a fan to create a wind tunnel on top of the aerofoil.

2. Daily life example: Why do passengers need to stand behind the yellow line at LRT station but not at the bus stand?

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Summative test question

1. The diagram shows air flows above the paper.

Which part of the paper has higher air velocity?

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2. State the relationship between the air velocity and its pressure.

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3. The figure below shows the positions of a ping pong ball before and after a stream of water flowing from a tap.

Before After

Explain why the ping pong ball is attracted to the flowing water.

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