Introduction to Engineering and Technology Concepts Unit Three Chapter One– The Six Simple Machines

Instructions for Success: Each chapter of every unit will begin with a “Mindjog.” This is a warm up question that you should answer in your workbook in the proper chapter. Please take notes as you move through the presentations in the notebook that has been provided. Sections will come up in each presentation with an assignment notice. Turn to the section detailed on the slide in your workbook and complete the assignment before proceeding. Good luck!

Objective Students will define the six simple machines, including the science and math concepts associated.

Mindjog! On your worksheet, please respond to the following question: “Think about the actual physical pieces that make a hammer. Now, compare that design to a pry bar…are there any similarities in regard to makeup? Why or why not?”

Common Components In the past unit, we have discovered how imagination and skill go into creating the plans for making technology. When looking at engineer drawings, one can begin to understand that artifacts have common components. These components can be labeled, “simple machines (Wright, 2004).”

Six Simple Machines Machines are artifacts that transmit or change the application of power, force, or motion. Simple Machines work on the two basic principles of the lever and the inclined plane. The Six Simple Machines are: The Lever The Wheel and Axle The Pulley The Inclined Plane The Wedge The Screw (Wright, 2004)

The Lever A lever has a rod or bar (the lever arm) that rests and turns on a support called a fulcrum. There are three categories of levers: –First Class places the fulcrum between the load and the effort. An example would be the pry bar. –Second Class sees the load between the effort and the fulcrum. An example of this would be the wheelbarrow. –Third class finds the effort placed between the load and fulcrum. A person moving dirt on a shovel would apply for this example (Wright, 2004).

Lever Classes, in detail Here are some visuals to better understand the lever classes: LEVER LOAD Fulcrum First Class: places the fulcrum between the load and the effort. Force/Effort Second Class: sees the load between the effort and the fulcrum. Force/Effort Third Class finds the effort placed between the load and fulcrum (Wright, 2004). Movement

The Wheel and Axle The Wheel and Axle is a shaft attached to a disk. Technically, this is another example of a second class lever, with the shaft or axle acting as the fulcrum and the circumference of the disk acting as the lever (Wright, 2004).

Pulleys Pulleys are grooved wheels attached to an axle. They also act as second class levers. Pulleys can serve three purposes:Pulleys can serve three purposes: -To Change Direction -To Multiply Force -To Multiply Distance (Wright, 2004).

Inclined Plane (Wright, 2004). A simple example of this would be a ramp that sits from the street to the back of a moving van.Inclined Planes are sloped surfaces used to make a job easier (Wright, 2004). A simple example of this would be a ramp that sits from the street to the back of a moving van.

Wedge (Wright, 2004). The blade of an axe is an example of a wedge.A wedge is another type of inclined plane that is used to spilt, separate materials, or grip parts (Wright, 2004). The blade of an axe is an example of a wedge.

Screw (Wright, 2004).The screw is another inclined plane, in that the inclined plane is wrapped around a shaft. It is considered a force multiplier (Wright, 2004).

Mechanical Advantage Using any of the six simple machines results in mechanical advantage (MA). Mechanical Advantage (MA) can be described as the benefit gained (in distance or force).Mechanical Advantage (MA) can be described as the benefit gained (in distance or force). To find mechanical advantage (MA) involves math, specifically multiplication.To find mechanical advantage (MA) involves math, specifically multiplication. Remember that using technology is about making things easier.Remember that using technology is about making things easier. How much harder would it be to lift a heavy weight without tying a rope and pulley around it ?How much harder would it be to lift a heavy weight without tying a rope and pulley around it (Wright, 2004) ?

Assignment #1 Please turn to the section in your workbook entitled, “Unit Three, Chapter One – The Six Simple Machines.” Complete the extension questions under the “Assignment #1” header before moving onto the next section of slides.

BEFORE MOVING ON: Did you complete the “Assignment #1” Section under the “Unit Three, Chapter One – The Six Simple Machines” section of your workbook? If you have, please proceed to the next slide.

Science/Math Concepts In this and other chapters, we have used terms such as force and energy. But, what exactly is force? What is energy? What about motion? Work? Efficiency? Before getting any further in this unit, we need to define these and other related terms.

Energy For any technology to benefit humanity, it needs an input in the form of energy. Energy is defined as the ability to do work. Energy can neither be created or destroyed. And if this is the case, then energy can only be what? Energy can only be converted from one form to another (Wright, 2004).

Energy (continued) Energy is in two forms: kinetic and potential. Kinetic energy is energy that being used. Potential energy is energy that is being stored. Think of a battery…alone the battery has the potential to be transformed and used. When placed in a device that runs on battery power, the energy becomes kinetic (Wright, 2004).

Work For the definition of energy, we stated that it is the ability to do work. But what is work? Work is applying a force that moves a mass a distance in the direction of the applied force. Work is measured in FOOT-POUNDS (ft.-lbs.) The math looks like this: Work = Force or Weight X Distance Imagine carrying a 10 pound bag of rice 13 miles. 10X13=130 ft.-lbs. Therefore, you have accomplished 130 foot-pounds (Wright, 2004).

Force So, work brought up the term force. Force can be described as a push or a pull. As you push down on a lever, you begin to gain MA (Wright, 2004).

Power Another term that is used incorrectly by interchanging with the term of energy is power. Power is the rate at which work is done. There are two common measurements: horsepower and kilowatt hour. Do these terms sound familiar? Car engines are measured in horsepower and light bulbs are measured in kilowatts (Wright, 2004).

Motion and Efficiency Motion can be described as movement in a direction. Being efficient means using less resources while meeting, at least, the minimum requirements. Efficiency will be something that we discuss heavily in the next chapter as well (Wright, 2004).

Assignment #2 Please turn to the section in your workbook entitled, “Unit Three, Chapter One – The Six Simple Machines.” Complete the extension questions under the “Assignment #2” header before moving onto the next section of slides.

BEFORE MOVING ON: Did you complete the “Assignment #2” Section under the “Unit Three, Chapter One – The Six Simple Machines” section of your workbook? If you have, please proceed to the next slide.

Chapter One Completed! Please close this presentation and launch the file entitled, “Chapter 2 – Energy.”

References Wright, R. (2004) “Technology” The Goodheart-Willcox Company, Inc.