Simple+Machines




 * __ Introduction __**


 * It is often said that a clever person finds ways to work smarter rather than harder. A machine can be defined as a device that makes a job easier to perform. A simple machine is a machine that does one type of job and has few or no moving parts (see pictures above), whereas a compound or complex machine can contain many simple machines and can perform more complex jobs. In this unit we will be learning about the different types of simple machines and investigate how they make work easier to do. We will also perform some simple experiments and calculations on forces and the amout of work done. I think we can all agree that less work is definately smarter, so this unit will help all of us to be a bit more clever.**


 * __Key words[[image:http://www.dugnorth.com/blog/uploaded_images/simple-machines-kit.jpg align="right" caption="external image simple-machines-kit.jpg"]]__ **

**Simple machine, compound machine, force multiplier, distance multiplier, speed multiplier, mechanical advantage, lever (first, second and third class), inclined plane, wedge, screw, wheel and axle, pulley, gears, cams, cogs, effort, fulcrum (pivot), load, energy, work, force, friction, mass, weight, spring balance**

**__Student work__**


 * 1.** Organising your student page: Create a new section on your student page, entitled ** Simple Machines ** .Consult your teacher for instructions. Class pages can be found here.

**2.** Working on a Glossary for Simple Machines (on your student page or in your notebook - consult your teacher for instructions).

Go to this website: @http://library.thinkquest.org/CR0210120/Mechanical%20Advantage.html Read the information and summarise on your wiki page or in your notebook. Then click the "inclined planes" box. copy down the information, diagram and the questions. Answer the questions then check your answers. Now... using what you have learned, fill-in the colum on your table of results by calculating the mechanical advantage produced by the cart and the block in your experiment. Lastly... answer any remaining Questions from the prac sheet you were given in class.
 * 3. Ramps experiment follow-up**. So... what is **mechanical advantage**?

Read through the information and answer questions 3, 4, 6, 7, 18, 19 and 20 on page 244.
 * 4. Following up from our evaluation of the ramps practical.**
 * Homework **: Go to your Science Focus 2 Textbook. Open and look at Unit 8, "Machines", p240-243.

Read through the information and answer questions 2, 3, 4, 5, 6, 7, 8, 9 and 10 on page 250.
 * 5. Levers: classifying as 1st, 2nd and 3rd class levers and class practical.**
 * Homework: ** Go to your Science Focus 2 Textbook. Open and look at Unit 8, "Machines", p247-250.

**6. Play this interactive game**, //Simple Machines in the House and The Toolshed//: **http://www.edheads.org/activities/simple-machines/**

...and in your notebook or on your wiki page give examples of simple machines you can find in two rooms of the house and then draw each of the four compound machines found in The Toolshed and label the simple machines that make them up.

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 * 7. Gears interactive:**

using this interactive simulation, design an experiment by changing one variable (independent) and measuring some other variable(s) (dependent) of your choice. Using the information you gather, determine how gear ratios can be used in a mechanical item like a bicycle.


 * 8.** **Go to** [] work your way through the simple machines simulations answering the questions as you go. These simulations will allow you to consider mechanical advantage to solve real-world problems using pulleys, wheels, levers and inclined planes. If you have not been provided with a printed version of the worksheets, click on "Parent/Teacher Lesson Plans" where you will find the worksheets to fill in.


 * 9**. **Processing Data Task:** go to [] and use the interactive applet on inclined planes to fill in the following worksheet

Using the diagrams above of pulley systems, deduce the mechanical advantage of using multiple pulleys. (the answer is quite a simple relationship - compare the input and output forces (F)) (in this case, acceleration is gravity, 9.8 m/s/s)
 * 10. Mechanical Advantage of Pulley Systems**
 * Force = Mass x Acceleration**

1. What did you find most interesting about simple machines? 2. What concepts or aspects did you find... i) the easiest ii) the most challenging 3. What would you be interested to investigate further regarding simple machines?
 * 11. Simple Machines - Reflection Questions**

**__Resources__**

Simple Machines Basic Introduction Powerpoint -



Simple Machines Mechanical Advantage Powerpoint -



Videos on simple machines - @http://educationalminimovies.com/SIMPLE-MACHINES.php Simple machines information sheet @http://www.uark.edu/depts/aeedhp/agscience/simpmach.htm Web page on mechanical advantage @http://library.thinkquest.org/CR0210120/Mechanical%20Advantage.html


 * __Videos__ **

See how many simple machines you can find in these crazy Japanese Rube Goldberg (chain reaction) machines

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Honda ad using Rube Goldberg machines

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Eureka! Videos - fun and informative

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