Systems in Action

1
Systems in Action

• This slideshow will guide you to learn about
• -different kinds of systems
• -purpose, input, and output
• -mechanical systems
• -calculating the work done by a machine
• -mechanical advantage
• -how systems improve over time

2
What is a system?

• Copy the definition into your notes
• A system is a single thing designed to perform a
  particular purpose. A system is made up of a
  number of parts (called elements or components)
  which work together to perform the systems
  function.
• Think of your body as a system
• Write a sentence to describe your bodys function
  or purpose.
• List 8 10 component parts of your body (e.g.
  skin, lungs) which work together (interact) to
  perform its purpose.

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Examples of Systems

• For each system, write down its PURPOSE, and FIVE
  components that interact to help it perform its
  purpose.

A Car
A Subway System
A Wheat Field
A City
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Purpose, Input, Output

• All systems have a purpose, input, and output.
• Example Car
• Input includes gasoline, oil, coolant
• Output includes motion, exhaust gases, heat
• A garden is an example of a system. Write down
  the purpose of a garden system, the inputs
  required for the garden to work, and the output
  of the garden.

A garden system
5
What is a Mechanical System?

• Use the reading about circus performers on pages
  96-97 to locate and write down the definition of
  mechanical system.
• Explain how the circus bike and the teeter totter
  work.
• List 5 more examples of mechanical systems

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Input and Output Forces

• In order for it to perform its function, a
  mechanical system has an input force (called
  Fin), and an output force (called Fout). To
  develop your understanding of these, read and
  take notes from the section INPUT AND OUTPUT
  FORCES on page 115.
• Draw simplified, labelled diagrams to show the
  input and output forces involved in a car jack
  and raising a flag on a flag pole from the
  textbook, showing the input and output forces.

Raising a flag
Car Jack
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MAY THE FORCE BE WITH YOU
Friction

• A force is a push or pull that acts on an
  object.
• To understand how Mechanical Systems work, we
  need to learn something about forces.
• Read page 99, and complete the organizer to learn
  about Contact Forces and Action-at-a-Distance
  Forces

Gravity
Magnetism
Static Charge
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How much do you weigh?
MEASURING WEIGHT AND FORCE Weight is actually
measured in Newtons (N), which is the unit for
force. Read page 101 to learn about Newtons.
There are 9.8 Newtons per Kilogram (9.8N/Kg). On
page 102, it explains how to calculate Newtons.
In your notes, calculate your own weight in
Newtons. Also, calculate the weight in Newtons
of a car with a mass of 1500Kg.

• MASS or WEIGHT
• If someone wants to know how much they weigh,
  they usually get an answer in Kilograms (Kg).
  But this isnt correct. A kilograms actually is
  a measure of mass. To learn the difference
  between mass and weight, read page 100, and
  complete the organizer in your notes.

Sir Isaac Newton
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Work Force x Distance
MEASURING WORK Study and take notes from page 110
to learn how to calculate work using the
formula (Work in Joules) (Force in Newtons) x
(distance in metres) Complete the calculations
on the top of page 111.

• Now that you have an understanding of Newtons,
  you will be able to calculate work. First, study
  pages 106 and 107 to learn the scientific
  meanings of work and energy. Define these in
  your notes.
• A Joule is the unit of measurement for energy.
• Work can be measured in Joules.

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Mechanical Advantage

• We design and use machines because they make work
  easier for us. The amount by which a machine can
  multiply an input force is called its MECHANICAL
  ADVANTAGE. Copy this definition into your notes.
  Study page 116-117 to understand mechanical
  advantage. Be sure to write the formula and
  describe clearly one of the examples either Wei
  or Jason.
• Complete questions 1 and 2 in Learning Checkpoint
  B17 on page 119.

Mechanical Systems are made up of one or more
simple machines which make work easier by
increasing the mechanical advantage. Skim read
page 130 140 to review the six simple machines.
Draw a labelled sketch diagram of each simple
machine in your notes.
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Systems Improve Efficiency

• EFFICIENCY
• Copy this definition into your notes
• The EFFICIENCY of a machine measures the useful
  work done by the machine compared to work needed
  to operate it.
• Skim read pages 144-148 to learn about
  efficiency.
• All SYSTEMS should be as efficient as possible.
  The Toronto subway system is currently in the
  process of having its old trains replaced by
  newer ones in an attempt to improve the systems
  efficiency.
• Think about and write a paragraph describing ways
  in which the subway system can be improved by
  buying expensive new trains.

New Subway Train, Toronto
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Getting Better All the Time

• Inventors and engineers constantly work to
  improve the many systems in the world.
• Choose one of the following systems. On a single
  slide, copy one picture of your system from 100
  years ago and one from today.
• Be prepared to show your slide and explain
  specific ways in which the system has been
  improved over the past century. Be sure to
  include ideas that can and cant be seen in the
  pictures.
• bicycle, farm, city, classroom, airplane, car,
  telephone, hospital, factory, road, house

100 year old bike
2013 Bike