Presentation on theme: "Systems in Action This slideshow will guide you to learn about: -different kinds of systems -purpose, input, and output -mechanical systems -calculating."— Presentation transcript:
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
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 system’s function. Think of your body as a system: -Write a sentence to describe your body’s function or purpose. -List 8 – 10 component parts of your body (e.g. skin, lungs) which work together (interact) to perform its purpose.
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
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
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
Input and Output Forces In order for it to perform its function, a mechanical system has an input force (called F in ), and an output force (called F out ). 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. Car Jack Raising a flag
MAY THE FORCE BE WITH YOU 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 Static Charge Magnetism Gravity Friction
How much do you weigh? MASS or WEIGHT If someone wants to know how much they weigh, they usually get an answer in Kilograms (Kg). But this isn’t 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. 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. Sir Isaac Newton
Work = Force x Distance 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. 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.
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.
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 system’s 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
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 can’t be seen in the pictures. bicycle, farm, city, classroom, airplane, car, telephone, hospital, factory, road, house… 100 year old bike 2013 Bike