Technology Education

MCAS Review2014

the material has the correct

PROPERTIES & CHARACTERISTICS

When choosing a material to make a product you must be sure that -

Is the material:

Property/Characteristic: a distinctive or distinguishing feature or quality

- soft or hard- flexible or non-flexible- clear or hard to see through- does it conduct electricity

Mechanical Properties

How a material reacts when a force is applied to it

Strength: Ability to withstand forces such as tension & compression

Elasticity: Ability to stretch out of shape & return to the original shape

Hardness: Ability to withstand scratches, dents & cuts

Fatigue: Ability to withstand bending & flexing

WoodWood is an organic and renewable material

Wood can be used for

Furniture, Fuel & Paper

PlasticPlastic is a Synthetic Material: Man made - Not found in nature

Plastic is formed into products using heat & pressure

Most plastics are made from petroleum

Metal

Mined from natural rock deposits

Metal can be processed into many different shapes

Metal is an inorganic material

PaperCreated by combining and bonding fibers

Most common source of these fibers is wood pulp

CeramicsMade from inorganic, mostly nonmetallic minerals such as clay, sand or quartz

High temperatures are used to fuse these minerals into useful products

AdhesivesAdhesives chemically attach two or more surfaces together

CompositesCreated by combining two or more materials to form a new material

This material is better than the original materials would have been on their own

Composites have become a popular material for sports equipment because they are lightweight & durable

SolventsSubstances that are capable of dissolving or dispersing one or more other substances

The most common solvent in every day life is: Water

ToolsInstruments that increase ability to do work

Hand Tools: Tools powered by human muscle

Measuring Tools: Used to identify size, shape, weight, distance, density or volume

Holding Devices: Protects the person and their

work piece from being injured or damaged when cutting, bending, drilling or hammering

Power Tools:

Tools powered by electricity

Tool Safety Rules Wear eye protection

Wear heat resistant gloves when working with hot materials Do not wear clothing that may get caught in spinning equipment - Roll up sleeves Keep fingers away from moving parts of machinery

Do not use tools to perform a job that it was not intended for

Always cut away from yourself

Use only tools that you have been instructed how to use properly

Wear ear protection

Wear steel-toed boots

Tool Safety Rules

Never walk away from a running machine

Concentrate on task when using equipment Do not work alone

Make sure the area is clear before you start a machine

Observe and follow safety signs and warnings

RED DANGER YELLOW CAUTION

Do not use dull tools

Do not use broken tools or equipment

EngineeringDesign Process

People that create technology follow this series of 8 steps

Step 1 Step 2 Step 3

Step 4

Step 5Step 6Step 7

Step 8

Identify the need

or problem

Engineering Design Process

Research the need or problem

What is the current state of the issue and current solutions?

Develop possiblesolution(s)

Brainstorm& list

Select bestpossible

solution(s)

Whichsolutionsbest solveoriginalproblem?

Construct a prototype

Model solution in2 or 3 dimensions

Test & evaluatesolution(s)

Does it work?How do you know?

Communicate the solution(s)

Make an engineering presentation that demonstrates how solution solves the original problem

Redesign(if necessary)

Modify solution based on info from

presentation & tests

Input ProcessOutpu

tGoal:What you wantthe system to do

Resources: (7)People, tools & machines, information, time, capital, energy, materials

The steps that lead to a result

The result that comes out of the system

FeedbackComparing the result to the original goal; adjustments are made to the inputs and/or

processes

Universal System Model of Technology

The most important resource (or input) for any technology is

PeopleWhy????????

Without PEOPLE there would be no technology

Components of a Communication System

Source

Encoder

Transmitter

Decoder

Receiver

Where the information begins / where the signal is sent from Examples: voice or image

Channel

Changes the information (message) into code so it can be sent (transmitted)

Sends the encoded message over a channel

Translates the encoded message into useful information so that it can be understood

Takes in the encoded message sent through the channel by the transmitter

Channel: The medium or link through which a signal is sent from the transmitter to the receiver Examples: wire cables, fiber-optic cables, wireless wave communication

Many communication systems often have 2 additional components that allow information to be saved so that it can be accessed when needed

Storage: Message is saved for later use

Retrieval: Message is recalled when needed

Examples: Voicemail / Telephone answering machine

Components of a Communication System

Books / Notebooks

iPods / MP3 Players / Cameras

CDs / DVDs / Blu-rays

Video Games

Computer hard drives / Flash drives

Icon/Symbol:

Icons & SymbolsA picture or image that is used to represent something elseAllows people to communicate without using words

Comparison of Custom Manufacturing & Mass

ProductionCustom Manufacturing Mass Production

Usually made in limited numbers

Same item produced many times

Made exactly as the person it is being made for wants it

Not made exactly how a person wants it

Made from start to finish by same worker (or small group of workers)

Workers only work on one part of the product

Worker(s) is/are usually a skilled craftsmen

Product is often machine made

Manufacturing:

Process of converting raw materials into physical goods (products)

Custom Manufacturing Advantages & Disadvantages

Custom ManufacturingAdvantages

Custom ManufacturingDisadvantages

You can get the product exactly how you want it

Usually has a higher cost

Product is unique – no one has exactly the same one

Product takes longer to make

Product is not easily replaceable

Mass Production Advantages & DisadvantagesMass Production Advantages & Disadvantages

Mass ProductionAdvantages

Mass ProductionDisadvantages

Product can be made quickly Will not be made exactly how you want it

Product can be made at a lower cost

Product will not be unique

Mass ProductionOne of the first products to be

mass produced was…

The Automobile

Henry Ford’s 4 Main Principles

of Mass Production

Reduction of Wasted Effort:

Henry Ford’s goal was to have his cars produced by workers without wasting time & effort

Henry Ford’s 4 Main Principles

of Mass ProductionInterchangeable Parts:Ford’s idea was to use a single part in as many different places in the car as possible to reduce costContinuous Flow:Car was constantly moving through assembly stations while the workers stayed in one place

Division of Labor:Workers were specialized & focused on one task when building car

Henry Ford’s 4 Main Principles

of Mass Production Interchangeable

Parts

ContinuousFlow

Division ofLabor

Reduction of Wasted Effort

Manufacturing Organizations

Groups of people or departments are responsible for specific parts of the manufacturing process

In many companies the overall process is led by the CEO (Chief Executive Officer)

CEO works with other leaders in the company to make sure that quality products are made and soldMarketing:

Makes sure company understands wants & needs of customerHelps determine what types of products should be made

Research & Development:

Researches & develops plan to make product after consulting with MarketingMeets with others department leaders to get plan for product approved

Production:

After the idea has been approved, this department mass produces the product

Quality Control:

Makes sure the product meets the appropriate standards when being produced

Trains workers & designs work areas to make sure that the workers are safe

Safety:

Sales:Sells the product (can sell directly to the public but usually they sell to companies that sell to the public )

Distribution:

Transports the product to where consumers can purchase

RobotsManufacturing companies have found robots to be very useful even though they are expensive

Robots

Take their instructions from a computer that has been programmed by a human

Can be programmed to do different tasks

Do jobs that are dangerous, boring or unpleasant for people

Production ProcessesSteps taken to convert raw materials into products

Process

Raw Material Product

Separating:Removing pieces of material to make it the size & shape you want

Cutting the object to make it the size you want

Sawing:

Makes a holeDrilling:

Shaping metal or wood dowels

Turning:

Forming:Changing the shape of the material – no material is added or taken away

Material is shaped by forcing part of it into a different position - metal & wood

Liquid material is poured into a mold, it takes on the shape of the mold as it hardens - metal, glass, plastic or clay

Bending:

Casting:

Shaping metal by heating it and then hammering it back into shape

Forging:

Softened material is squeezed through a small opening (pipe & wire)

Extruding:

Combining:

Joining materials together to make finished product

Using small piece of metal or plastic to hold parts together (Nails, screws, staples, nuts & bolts, rivets, etc.)

Mechanical Fastening:

Combining:

Joining materials together to make finished product

Using small piece of metal or plastic to hold parts together (Nails, screws, staples, nuts & bolts, rivets, etc.)

Heating materials so that they soften & flow into each other(Welding & Soldering)

Mechanical Fastening:

Heat Fastening:

Holds things together without a separate fastener(CD Case)

Snap Joint Fastening:

Using adhesive to stick parts togetherGluing:

Finishing:The last step in making a product - used to improve it’s appearance and/or performance

To make flatSmoothing:

Paints, clear finishes or plastic

Coatings:

To make glossyPolishing:

House Construction

A House…

Provides people with shelter & storage

Foundation: The part of the house that rests on

the ground and supports the upper structure

All buildings require a solid foundation or the building cannot be constructed properly

Subfloor:

First layer of flooring nailed to the floor joists Usually sheets of

plywood

Wall Studs:Pieces of lumber, usually 2 x 4’s, used for the framework of walls

Sheathing:Nailed to wall framework to enclose structure on the outside. Made of plywood or particleboard

Roof: Keeps precipitation out

Stabilizes the walls

Roof Decking:

Sheets of lumber (usually plywood) nailed to the outside of the rafters (or trusses)

Asphalt Shingles are nailed to the roof decking over a layer of heavy asphalt paper – Shingles weatherproof the roof

Roof Shingles:

Cross Section View of House

If you want to remove a wall in a house you must

make sure that it is not a WEIGHT BEARING wall

Siding:

Put on the outside for protection from the weather - attached to sheathing - made of wood, metal, brick, vinyl, etc.

Insulation: Material used to keep heat or cold

from leaving or entering a building

Rolls made to fit between floor joists, ceiling joists and wall studs

Most popular form is fiberglass

Drywall:Inside covering of walls and ceilings, made from plaster and sturdy paper (commonly referred to as Sheetrock)

Sheets are screwed to the walls and ceilings - cracks & screws are covered with tape & spackling (joint compound)

A structure built to span a physical obstacle such as a road, valley, railroad track, river, or any other body of water

Bridge:

Forces Upon Bridges

A force that pushesCompression A force that pullsTension

A force that twistsTorsion

A force acting across any beam or structural element

Shear

Behavior of a structural element subjected to an external load applied to it

Bending

Most common type of bridgeOldest type of bridge (log over stream)Commonly used on roadways that cross over highways or other roads

Frequently supported by piers partway along the span because of the heavy weight of the beam

Can span distances up to 250 feet

Beam Bridge

Arch Bridge

First Arch Bridges were made of wedge shaped stones locked in a curve (Keystone)

Arch bridges distribute weight sideways and down around the curve

Used to cross very wide spans (2000 - 7000 ft)

Suspension Bridge

Bridge is suspended (hangs) from large vertical cables

Transportation TechnologySystems & devices that move goods & people from one place to another across or through Land, Air, Water & Space

Travel over land in a car, bus, train, bicycle, motorcycle, subway, etc.

Land Transportation:

Used for personal land transportationAutomobile:

Mass Transportation: Moves many people at one time and is available to the general public

Mass transportation is sometimes slower & less convenient than personal transportation but it is cheaper

Move much of our country’s freight

Trucks:

Railroads earn most of their money by hauling freight - they are used to deliver bulky goods

Trains:

Trains also carry passengers

Operated by AMTRAK - intercity passenger railroad

In the US trains carry less than 1% of all intercity passengers

High Speed Trains:

All-electric

Travel at 125 - 200 mph

Maglev Trains:

Magnetic levitation - doesn’t touch the ground - no wheelsPropelled by magnets

Floats 1 inch above it’s track - produces very little vibration & are very quietExpensive - so only a few experimental guide ways have been built in the US

Water has provided transportation routes for centuries

Water Transportation:

Passenger ships/boats transport people

Cargo ships transport things (oil, grain, iron ore, automobiles, etc.)

Ships deliver most of the overseas cargo leaving or entering the US

Usually the least expensive way to transport goods

Airplanes: Most important part of our air transportation system

Because many planes are in the air at one time - air travel is our most complex transportation system

Some planes carry only cargo

Cannot carry as much cargo as a ship or train

Air transportation is very expensive

Helicopters: Aircraft with one or two rotors that allow it to lift straight up

Space Transportation:

NASA is responsible for regulating and directing the entire US space program

Currently consists of unmanned vehicles for exploration

Space vehicles take us beyond the earth

Transmission

Transfers power fromthe engine to theaxles and wheels:

Structure and support:

Propulsion:

Guidance:

Suspension:

Control:

GPS

Frame

Engine

Steering

Springs & shock absorbers

Brakes & Steering

Navigation:

Automobile Subsystems: When all subsystems work together the car functions properly

Have inputs, process, outputs & feedback

Universal Systems Model of a City Bus System

Inputs:

Process:

Output:

Feedback:

Goal (Safe arrival at scheduled stops), Buses, people to operate buses, fuel to provide energy, schedules, passengers

Loading passengers, driving the bus

Safe arrival at scheduled stops

Comments from satisfied customers

Transportation Systems

AerodynamicsThe study of the motion of the air when

it interacts with a moving object

Lift:

Force: A push or pull in a specific direction

Weight:

Force caused by thegravitational attraction of the Earth on the planeForce created by the

engines that move the plane through the air

Drag:

Force that opposes (tries to stop) the plane’s motion through the air

Thrust:

Force created by a solid object (plane) moving through a fluid (air)

WEIGHTFor the plane to fly, it’s LIFT must be greater than it’s

The shape of the airplane’s wings is what creates the LIFT that makes the airplane fly

The flat surface of the bottom of the wing means that there is more friction so the air moves slower - this means that there is more pressure under the wing

The curved surface of the top of the wing means that there is less friction so the air moves faster - this means that there is less pressure over the wing

Weight:

Force caused by thegravitational attraction of the Earth on the carForce created by the engine to

move the car through the air

Drag:

Force that opposes (tries to stop) the car’s motion through the air

Thrust:

Drag

Thrust

Spoiler: Reduces Lift (opposite of the wings of an airplane)

Forces on a Race Car

Bioengineering Technology:Technology that is used to analyze & solve problems related to human health

Considered the fastest growing technology todayAdaptive & Assistive Devices:

Products that help maintain, increase or improve an ordinary human function

Wheelchairs, Eyeglasses, Contact Lenses, Braces, Artificial Limbs, Bionics

Irradiation:Process in which food is briefly exposed to a source of radiation (x-rays or electron beam). This cooks the food slightly, kills parasites, insects, bacteria & controls moldsFoods have a longer shelf life and are less likely to cause food poisoning

Biofuels: Fuels made from agricultural products

Reduce our dependency on oil as a source of energy – cleanerAny plant that produces sugar or starch can be used as a biofuel

Integrated Pest Management:

An attempt to reduce dependency on harmful chemical pesticides

Alternative solutions to the pest problem are researched before any chemicals are used

Using strains of crops that are resistant to a particular pest

Using other animals as a natural form of pest control

Chemicals are used as a last resort and are used sparingly