Unit 2 - Energy, Modern Materials and Devices Flashcards
(30 cards)
give examples of fossil fuels:
coal oil and gas which is heated to drive turbines.
what is fracking?
Fracking involves drilling into layers of shale rock deep in the earth to release pockets of gas
list different types of renewable energy:
solar
wind
hydroelectric
biomass
tidal
what are photovoltaic cells?
Light photons hit the PV cell which allows electrons to flow, creating an electric current
what is hydroelectricity?
Hydroelectric power works by harnessing the power of moving water to generate electricity
what is tidal?
The rise and fall of the tide forces water through turbines which drive generators to produce electricity
list different types of potential and kinetic energy:
potential: stored in objects not in motion, that will move once released
Chemical
Mechanical
Nuclear
Gravitational
kinetic: Kinetic energy involves motion and movement
Movement
Electricity
Heat
Sound
Light
why use rechargeable batteries against normal?
cost savings, environmental benefits, and convenience
Batteries contain toxic chemicals and metals which:
leach into the soil and water table
are harmful to wildlife and the natural habitat
need specialist recycling
what is the difference between Pneumatics and hydraulics?
pneumatics - pumped air or gas.
hydraulics - pumped and compressed liquid is used instead of air which creates a more powerful system
what are modern materials?
New and improved materials are
constantly being discovered and developed
what is Polycaprolactone (PCL)?
Polycaprolactone (PCL) is a low temperature, hand-mouldable polymer
what are smart materials?
Smart materials react to an external stimulus by changing their characteristics and/or properties
what do self healing polymers do?
react to stress fractures by releasing a resin into the new crack
describe photochromic particles.
hint: sunglasses
Ultraviolet light reacts with photosensitive silver halide particles within the lenses
what are piezoelectric materials?
Piezoelectric material works in two ways:
Subject it to movement or stress and it produces electricity
Attach an electrical signal to it and it moves
what is a composite material?
A material that is composed of two or more materials combined to improve their properties
what can technical textiles be used for in clothing?
Weatherproofing
Strengthening
Adding conductivity
and insulation, both
thermally and electrically
how does gore-tex work?
allows water vapour to get through but not water droplets.
what are subsystems?
Subsystems or subtasks are events or tasks that happen within a system
what do flowchart symbols represent?
circle = start and end
parallelogram = input output
rectangle = process
diamond = decision
what is the difference between open and closed loop systems?
Open loop systems do not make decisions based on feedback
closed loop make decisions on feedback.
give examples of input, process and output devices.
input =
scanner
mouse
keyboard
process =
CPU
output =
speaker
printer
projector
what is the difference between analogue and digital signals?
Analogue signals have an infinite range of values
between the minimum and maximum points
Digital signals are either on or off, and are usually represented by a 0 for off and a 1 for on
what can ICs do?
Also known as microchips, ICs are capable of performing specific tasks
