|
GCSE level physics exam revision notes all about forces Part 6
Forces and pressure: 6.5
Some applications and uses of
hydraulic systems -
jacking up cars, plant machinery, diggers, bulldozers,
elevated platforms
[Author
©
Dr Phil Brown PhD:
Doc Brown's physics exam revision notes suitable for students of UK
IGCSE & GCSE level physics courses, ~ US grades 9-10 physics
[forces-6- page updated
Mar 16th 2026 *]
[ KEY
POINTS and learning objectives for this page, after initial notes]
email doc
brown: problems?, comments? query?
*
[privacy & cookies policies & disclaimer]
What do we use hydraulic
systems for?
Sub-index for physics notes on 6.
Forces and Pressure in fluids and calculations
6.5
Some applications of
hydraulic systems
Reminders and uses:
Hydraulic machines use liquid fluid power
to perform light or heavy work in many situations.
Heavy construction/demolition/digging
vehicles are a common examples (illustrated below).
In these machines, hydraulic fluid is
pumped to various hydraulic motors and hydraulic cylinders throughout the
machine and becomes pressurized sufficiently to overcome resistance and
effect movement.
The fluid is controlled directly or
automatically by control valves and distributed through tubes/pipes.
Hydraulic systems, like pneumatic
systems, are based on the fact that any pressure applied to a fluid inside a
closed system will transmit that pressure equally everywhere and in all
directions.
To be effective in transmitting
force, hydraulic systems must use an in-compressible liquid as its
fluid, rather than a compressible gas.
The wide-spread use of hydraulic machinery is because large amounts of
power that can be transferred mechanically, and relatively simply,
through small tubes and flexible hoses to achieve movement e.g. lifting
or digging.
(1) Hydraulic jack system
for lifting vehicles in garages
Four hydraulic piston and cylinder systems are used to jack up the red van. The
fluid can be oil or compressed air.
(2) Car hydraulic braking systems
The Land Rover (left) and the red van (right) both have
hydraulic brake
systems
Key for the 5 photographic diagrams:
S =
suspension spring; H = the pipe conveying the hydraulic brake fluid
force.
D = the brake drum and disc on which the brake pads in
casing P are forced into contact with the smooth disc by the hydraulic
transmitted force when you press the brake pedal.
A conveys speed of rotation information for the correct
functioning of the advanced ABS braking system.
How does the hydraulic brake system of a motor vehicle work?
When you press on the brake pedal of motor vehicle, the force is
transmitted through the brake fluid liquid by a pipe system (in modern cars it
is aided by an electric pump system).
The braking mechanism involves several
pistons and cylinders, known as the master cylinder (activated by the pedal) and
slave cylinders on the brake drums (4 of the latter in the case of 4 wheeled
vehicles).
The transmitted force pushes the brake pads onto the brake disc on
the brake drum and the resulting friction reduces the speed of the vehicle.
When
you take you foot off the brake pedal, the force is no longer transmitted and
springs move the brake pads away from the brake discs to avoid unnecessary
friction.
'Hydraulic' photographs by courtesy of Mark Raw of M T R
Autotech Ltd garage, Castleton, North Yorkshire, England
(2) Plant machinery - examples of
using hydraulic machinery
A huge range of excavators
('diggers'), diggers, bulldozers, elevated work platforms are used on demolition sites,
construction sites use liquid power in hydraulic systems.
In the above photographs you can see
the shiny steel systems of the hydraulic systems.
Index physics Forces notes 6. Forces & pressure in
fluids, calculations
Key points
about
forces in fluids - hydraulic system applications
Information
sources for Doc Brown's key points: IGCSE-GCSE physics are based on
textbooks & syllabus-specifications for students taking the UK AQA, Edexcel,
OCR 21st Century Science, OCR Gateway science suite, WJEC, CCEA and CIE GCSE
physics 9-1 level science examinations
A structured set of summary
revision notes on applications of hydraulic systems
(excluding calculations), tailored to the major UK GCSE/IGCSE
physics exam boards: WJEC, CCEA, CIE, AQA, Edexcel, and OCR.
These notes focus on real-world uses, physics principles, and exam-relevant
content.
What Are Hydraulic Systems?
- Definition:
Systems that use incompressible liquids to transmit force
via pressure.
- Principle:
Based on Pascal’s Law — pressure applied to a confined
fluid is transmitted equally in all directions.
- Key Feature:
Allows force multiplication — a small input force can
produce a large output force.
Real-World Applications of Hydraulic Systems
| Application |
Description |
| Hydraulic Brakes |
Used in cars and bikes; pressure from
brake pedal is transmitted to brake pads. |
| Hydraulic Lifts |
Found in garages and elevators; lift
heavy loads with small input force. |
| Hydraulic Jacks |
Used to raise vehicles for
maintenance; compact and powerful. |
| Aircraft Landing Gear |
Hydraulics deploy and retract gear
smoothly and reliably. |
| Construction Machinery |
Excavators, bulldozers, and cranes use
hydraulics for lifting and digging. |
| Hydraulic Presses |
Used in manufacturing to shape or
compress materials. |
| Theme Park Rides |
Control motion and safety systems
using hydraulic actuators. |
| Dentist Chairs |
Smooth vertical movement for patient
comfort and access. |
Typical Board-Specific Syllabus Content
- Emphasises Pascal’s Law
and force transmission
- Includes brakes, lifts, and
presses as examples
- Focus on real-world relevance
and system design
- Covers hydraulic applications
in transport and industry
- Encourages understanding of
pressure transmission
- Includes practical contexts
like jacks and brakes
- Requires explanation of
hydraulic system uses
- Focus on
equal pressure transmission
- Includes brakes, lifts, and
presses in syllabus
- Triple science includes
hydraulic systems as force multipliers
- Focus on
brakes and lifting systems
- Higher tier may explore Pascal’s
Principle in context
- Covers hydraulic applications
in engineering and transport
- Emphasises real-world examples
and pressure transmission
- Includes
brakes, jacks, and presses
- Includes hydraulic systems
in forces in action
- Focus on
uses and pressure transmission
- Examples include
brakes, lifts, and presses
Student Tips for Exam Success
- Understand Pascal’s Law:
Pressure is transmitted equally in all directions.
- Link examples to pressure
transmission: Explain how
force is multiplied.
- Use diagrams:
Show pistons, fluid flow, and force directions.
- Avoid calculations:
Focus on conceptual understanding and applications.
- Revise terminology:
Input/output piston, actuator, incompressible fluid.
- Use past papers:
Identify how applications are assessed in your board.
Keywords, phrases and learning objectives for forces involving
pressure situations
Be able to describe and explain applications and uses of hydraulic systems
e.g. jacking
up cars, plant machinery like diggers and bulldozers, elevated platforms
for maintenance.
Know that hydraulic systems work by the transmission of force
through a liquid to create pressure, or applying pressure to produce
an applied force in machines.
importance of
describing & explaining examples of hydraulic pressure applications
in GCSE level physics, What you need to know about describing &
explaining examples of hydraulic pressure applications for
GCSE level
physics,
Explaining the use of describing & explaining examples of hydraulic
pressure applications knowledge in GCSE level physics, Examples of
describing & explaining examples of hydraulic pressure applications explained
when studying GCSE level physics, What is
significant about describing & explaining examples of hydraulic pressure
applications, describing the theory of describing & explaining
examples of hydraulic pressure applications when studying
GCSE level physics, revision notes for describing & explaining examples
of hydraulic pressure applications in exams, online exam help
for describing & explaining examples of hydraulic pressure applications, revision notes about
describing & explaining examples of hydraulic pressure applications, what do I need to learn about
describing & explaining examples of hydraulic pressure applications for
by GCSE physics exam?
help to understand the describing & explaining examples of hydraulic
pressure applications topic in preparation for GCSE physics exam
question, how to
prepare for questions involving describing & explaining examples of
hydraulic pressure applications in a GCSE physics examination?
Revision notes on describing & explaining examples of hydraulic pressure
applications based on the syllabus-specifications
for students taking IGCSE/GCSE level physics examinations, summary
revision notes and key points on describing & explaining examples of
hydraulic pressure applications for students taking the AQA
igcse/gcse physics notes on describing & explaining examples of hydraulic
pressure applications, Edexcel gcse
physics notes on describing & explaining examples of hydraulic
pressure applications, OCR 21st century GCSE
physics notes on describing & explaining examples of hydraulic
pressure applications, OCR gateway
GCSE physics notes on describing & explaining examples of hydraulic
pressure applications, WJEC gcse physics notes on describing &
explaining examples of hydraulic pressure applications, CCEA
gcse physics notes on describing & explaining examples of hydraulic
pressure applications for students taking CIE Cambridge igcse
physics, exam revision notes on
describing & explaining examples of hydraulic pressure applications, useful for US grade 9-10 physics courses
SITEMAP
Website content © Dr
Phil Brown 2000+. All copyrights reserved on Doc Brown's physics revision notes, images,
quizzes, worksheets etc. Copying of website material is NOT
permitted. Exam revision summaries and references to GCSE science course specifications
are unofficial.
Index physics Forces notes 6. Forces & pressure in fluids, calculations
|
