Unit 1

Front 1

Simple machines

Back 1

comprise most mechanisms; redirect energy by manipulating force, distance, and/or speed

Front 2

Mechanical Advatage formula

Back 2

MA=R/E

R=magintude of resistance force
E=magintude of effort force

Front 3

Levers

Back 3

Class 1: fulcrum between load and effort
Class 2: load between effort and fulcrum MA>1
Class 3: effort between load and fulcrum MA<1

Front 4

Moment

Back 4

Force*Distance

Equilibrium: E*Le=R*Lr

Front 5

Wheel & Axle IMA

Back 5

IMA=De/Dr
MA=R/E

Front 6

Pulleys

Back 6

change direction and magnitude of a force
MA= # of strands
(only count last strand if pointing up)
AMA=Fr/Fe

Front 7

Gear Ratios

Back 7

Change: -speed of direction
-direction of rotation
-amount of torque available to do work
GR/1=Nout/Nin=Dout/Din=Win/Wout=Tin/Tout

GR= gear ratio N= # of teeth D=diameter
W= angular velocity T=torque

Front 8

Inclined Plane

Back 8

IMA=De/Dr
IMA=L/H

De=distance traveled by effort=L
Dr=distance traveled by resistance=H

Front 9

Wedge IMA

Back 9

IMA=De/Dr
IMA=L/T
De=distance traveled by effort=L
Dr=distance traveled by resistance=T

Front 10

Screw IMA

Back 10

IMA=De/Dr
IMA=Circumference/Pitch=2piRe/P

De=one rotation of effort arm=circumference
Dr=linear distance traveled during one rotation of effort arm=Pitch

Front 11

Energy Sources

Back 11

Energy- ability to do work

Front 12

Nonrenewable Energy Sources

Back 12

Fossil fuels
Uranium

Front 13

Renewable Energy Sources

Back 13

Animal
Food
Biomass

Front 14

Inexhaustible Energy Sources

Back 14

Hydroelectric/Tidal
Geothermal
Wind
Solar

Front 15

Work

Back 15

product of force (F) applied to object over distance (d) in which object travels as a result
W=F*d
Joule is base unit= 1 newton * 1 meter

Front 16

Power

Back 16

rate at which work is performed or energy is expended

P=work/time
watt is base unit= 1 joule/second

Front 17

Mechanical Winch

Back 17

Powerout=work/time
Powerin=voltage*current
Efficiency=(Pout/Pin)*100

Front 18

Conservation of energy

Back 18

energy cannot be created or destroyed, but can change forms

Front 19

Energy Conversion

Back 19

changing one form of energy to another

efficiency- useful energy : energy supplied

Front 20

Entropy

Back 20

loss of energy during conversion

Front 21

Electrical Circuit

Back 21

system of conductors and components forming a complete path for current to travel

Front 22

Voltage

Back 22

force (pressure) that causes current to flow; Volts; V

Front 23

Current

Back 23

flow of electric charge; Amps; A

Front 24

Resistance

Back 24

opposition of current flow; Ohms; omega

Front 25

Ohm's Law

Back 25

V=IR

V- voltage I- current R- resistance

Front 26

Series Circuits

Back 26

components connected end-to-end
simgle path for current to flow

Front 27

Parallel Circuits

Back 27

both ends of components are connected together
multiple paths for current to flow

Front 28

Series Circuit Formulas

Back 28

Current stays equal everywhere
Resistance adds to total resistance
Voltage adds to total coltage

Front 29

Parallel Circuit Formulas

Back 29

Voltage stays equal everywhere
Current adds to total current
Total resistance is equal to reciprocal of the sum of the reciprocal

Front 30

Hydrogen Fuel Cell

Back 30

creates electricity and heat through electrochemical process that converts hydrogen and oxygen to water

Front 31

Thermodynamics

Back 31

study of effects of work, heat flow, and energy on a system

movement of thermal energy

Front 32

Thermal Energy (heat transfer) Transfer

Back 32

transfer of movement of thermal energy

100% efficiency is unattainable

Front 33

Convection

Back 33

movement of air

Front 34

Conduction

Back 34

movement through an object through touching

Front 35

Radiation

Back 35

electromagnetic waves

Front 36

Calculating Energy Transfer

Back 36

Q=U*A*changeinT

Q- energy transfer U- U value A- area T- temperature

Front 37

Design Process

Back 37

a systemartic problem solving strategy to reach a final choice

Front 38

Design Brief

Back 38

-defines problem
-concise
-identifies client
-clearly states problem
-lists specificationa and constraints

Front 39

Design Team

Back 39

collection of individuals who each use their own expertise to help benefit a common goal

Front 40

Define a problem

Back 40

recieve a problem

Front 41

Braistorm

Back 41

generate and record ideas
develop prelminary ideas based on constraints

Front 42

Generate and research ideas

Back 42

conduct interviews
generate and compile ideas

Front 43

Identify criteria and specific constraints

Back 43

identify constraints
draft the design brief

Front 44

Explore possibilities

Back 44

consider futher development
explore alternative ideas

Front 45

Select an approach

Back 45

use a decision matrix

Front 46

Develop a design proposal

Back 46

explore idea in detail
sketches/models
make critical decisions on material and process

Front 47

Make a model or prototype

Back 47

build

Front 48

Test and evaluate the design using specifications

Back 48

trial runs

Front 49

Refine the design

Back 49

modify design

Front 50

Create solution

Back 50

final design

Front 51

Communicate processes and results

Back 51

using media
marketing
distribution