1. Pressure in Liquids
Problem/challenge/misconception: Students have a common misconception that liquid pressure depends on surface area.
Topic: Understanding Atmospheric Pressure.
Approach: Inquiry-discovery.
Method: Investigation - Experiment.
Strategy: Students observe water spurting out from a container through holes at different depths.
Students make an inference, propose a hypothesis and plan an experiment to verify the
hypothesis.
Experiment: Refer to Appendix 1.
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2. Pressure in Liquids
Date:
SUBJECT: PHYSICS
YEAR: FORM 4
LEARNING AREA: 3. FORCES AND PRESSURE
LEARNING OBJECTIVE: 3.2 UNDERSTANDING PRESSURE IN LIQUIDS
LEARNING OUTCOMES: A student is able to:
1. Relate depth to pressure in a liquid.
2. Explain pressure in a liquid and state that
P = hρg
3. Describe applications of pressure in liquids.
4. Solve problems involving pressure in liquids.
Time: 2 periods (80 minutes)
Subject Content: Liquid pressure and depth of liquid.
Suggested Activities: 1. Students are asked to discuss a situation whereby:
i. 5 water hoses of different lengths are filled with water.
ii. These hoses will be hung from different heights.
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3. Pressure in Liquids
2. Oral and written questions are given in a logical sequence to assist students in making
inference and hypothesis.
3. Students conduct an experiment to investigate the relationship between the depth of the liquid
and liquid pressure.
4. Students discuss the result in groups.
5. One group will present their findings and conclusion.
6. Teacher will then guide students on using the reinforcement module.
Moral Values: Being honest and cooperative
Creative and Critical Thinking Skills: Making inferences and hypotheses
Teaching Aid: Water hoses, metre rules, rubber stoppers, laptop PC and LCD projector, MOE Physics
Teaching Courseware .
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4. Pressure in Liquids
STAGES CONTENT SUGGESTED ACTIVITIES
RESOURCES /
REMARKS
Set Induction
(10 minutes)
1. Students are shown five water hoses of different
lengths.
(Refer to Appendix 1 for the diagram.)
2. Students are asked questions relating to water spurting
out of the hoses.
3. Students have to state their
i. observations
ii. inferences
iii. hypotheses
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5. Pressure in Liquids
STAGES CONTENT SUGGESTED ACTIVITIES RESOURCES /
REMARKS
Development
STEP 1
(30 minutes)
1. Students are given 5 water hoses of different lengths,
metre rules and 5 rubber stoppers.
2. Students are asked to
i. Arrange the apparatus as shown in the diagram in
Appendix 1.
(Suggested lengths of the water hoses : 5.0 m,
4.0m, 3.0 m, 2.0 m and 1.0 m respectively).
ii. Cover one end of each hose and then fill it with
water to the brim.
iii. Remove the rubber stopper for Hose A and measure
the horizontal distance, xA, travelled by the water
spurt.
iv. Repeat step 2(iii) for hoses B, C, D and E
respectively and measure the horizontal distances
Laptop PC and LCD
projector
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6. Pressure in Liquids
STEP 2
(20 minutes)
Analysis
xB, xC, xD and xE.
v. Tabulate the results for the depth of water, h and the
horizontal distance, x.
vi. Plot a graph of horizontal distance, x against depth
of water, h.
1. Students are questioned on their observation.
Q1: What does the distance, x, represent?
(Water pressure)
Q2. Are there other ways of measuring water pressure
without using any standard pressure-measuring
device?
Q3: From the graph of x against depth of water, h,
(a) state the relationship between x and h,
(x is directly proportional to h)
(b) determine the value of x if h is 8.0 m.
2. Teacher explains the concept of pressure in liquids.
Laptop PC and LCD
projector
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7. Pressure in Liquids
STAGES CONTENT SUGGESTED ACTIVITIES RESOURCES /
REMARKS
STEP 3
(15 minutes)
Problem Solving
1. Teacher gives some examples of problem-solving
involving pressure in liquids.
2. Teacher gives a few questions for students to answer
verbally.
3. Teacher and students discuss the answers.
Laptop PC and LCD
projector
Closure
(5 minutes)
1. Teacher summarises the lesson.
2. Students are asked to finish the report at home as well as
answering the reinforcement questions in the module.
(Refer to reinforcement module.)
Laptop PC and LCD
projector
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8. Pressure in Liquids
Appendix 1
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Three-storey School Block

9. Pressure in Liquids
Summative Test
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Water spurting
Diagram 1: Pressure in Liquids :
Five long water hoses in action from
different heights at a school block
Hose E
Hose C
Hose A
Hose B
Hose D

10. Pressure in Liquids
1. Compare the liquid pressure at the points P, Q and R in the diagrams below.
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P Q R S