KS3 Physics Lesson Plan
Pressure in Liquids
Lesson provided by Vicki Dennison
Background
The study of hydraulics can be daunting, especially for students who are not confident
with science or who struggle with numeracy, for whom the mathematical aspects of this
important scientific principle can be off-putting. Diagrams are great for helping students
visualise the processes in a hydraulic system, which are often
difficult to observe in real-life examples.
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Aim
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The aim of this lesson is to introduce the principles
and applications of hydraulic systems in a fun and
accessible way, using clear visual examples, and
engaging students by allowing them to make their
own egg box ‘monsters’.
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works.co.uk
The activity
To start, I use slide 2 of the sample material
taken from the Boardworks KS3 Physics
presentation, ‘Pressure and Moments’, to
introduce the idea that hydraulic systems
allow a force to be transferred within a
machine because the pressure throughout the
system remains constant.
s, Pressure
in Liquids,
Slide 2
Next, using
slide 3, I provide a
clear visual representation of hydraulics in car
brakes. This is a concept which the majority of
students will be aware of, so it provides a good
starting point for introducing applications of
hydraulics. I then move on to talk about another
real-life example of hydraulics in action: the use
of animatronics in puppetry. Hydraulics allows
puppeters to control their puppets remotely. A
simple example of this is opening and closing
the puppet’s mouth.
KS3 Physic
s, Pressure
in Liquids,
Slide 3
Or
Boardworks Ltd
The Gallery
54 Marston Street
Oxford, OX4 1LF
KS3 Physic
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Sample Dis
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0845 0 300
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t: 0845 0 300 400
f: 0845 0 300 200
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www.boardworks.co.uk
KS3 Physics Lesson Plan
Pressure in Liquids
I then move on to a practical task where I get students
to construct a ‘hydraulic system’ using two syringes
connected via a rubber tube. Filling these with
water is possible, but potentially messy. Using air
in the system still provides a good demonstration
of the transfer of force and movement.
I get students to decorate an egg box, with the
front of the box forming a mouth. By making a
hole in the bottom of the box, the rubber tube
can be fed through, and the slave piston secured
inside using blu-tack. Students can then use the
master piston to control their ‘monster’s’ mouth.
KS3 Physic
s, Pressure
in Liquids,
Slide 4
Using air in the system means that there is a delay in
the transfer of movement, which provides a great
starting point for discussions about why hydraulic
fluid is used instead of a gas. Slide 4 then offers
a fantastic animation showing how the pressure
within a closed system containing a gas changes
as a force is applied.
At the end of the lesson, I use slide 5 to assess
students’ learning, checking that they are aware
of the terms ‘master cylinder’ and ‘slave cylinder’,
and relate these back to the car brake example.
KS3 Physic
s, Pressure
in Liquids,
Slide 5
Outcomes
Students thoroughly enjoy taking part in this hands-on
activity which demonstrates genuine applications of hydraulics.
The clear diagrams and animations in the Boardworks resources allow students to visualise
what is happening within a hydraulic system, and provide a sense of relevance for further
study of the topic. Once an understanding of the basics has been established, simple
calculations of pressure in hydraulic systems can be introduced (using slides 7 and 18 from
the full Boardworks ‘Pressure and Moments’ presentation). The ‘fill-the-gaps’ summary
activity (slide 20 in the full presentation) can be used to assess students’ understanding of
pressure.
Or
Boardworks Ltd
The Gallery
54 Marston Street
Oxford, OX4 1LF
d
r FREE Sampl
You
eD
r
e
i
interactive
Inspiring, re for teachers
wa
soft
whole-class
c
Sample Dis
400
0845 0 300
k
sc
t: 0845 0 300 400
f: 0845 0 300 200
[email protected]
www.boardworks.co.uk