P13 - P27 Y10 Flashcards
When did the last UK coal powered power station close
The last UK coal powered power station closed on the 30th of September 2024, ending 142 years of coal use in the UK and made us the first country to stop using coal to generate energy
Turbines and generators
Production of electricity involves rotations a turbine which turns a generator
Fossil Fuels
Fossil fuels are finite resources, they produce carbon dioxide which contributes to climate change
Advantages of fossil fuels
A cheap and reliable source of energy well developed systems to harness the energy
Disadvantages of fossil fuels
Contains high amounts of carbon and contributes to the global warming
A non renewable and unsustainable energy source
Accidents such as oil spills contribute to pollution and environmental contamination
Shale Gas
Shale Gas is a natural gas trapped in the earths crust, hydraulic fracturing or fracking is a process for extracting the gas from the shale
Describe the process of ‘Fracking’
Sends a high pressure mixture of water, sand and chemicals into the rock to release the gas
How is Nuclear power generated
A nuclear power plant produces energy through a process called fission - the splitting of uranium atoms in a nuclear reactor.
Advantage and disadvantages of Nuclear power
Nuclear power is clean and efficient, however the waste material is radioactive and dangerous to life the waste fuel requires specialist handling , decommissioning and lots of storage space
How much energy can a kilogram of uranium release
A kg of uranium can release 3 million more types of energy than coal
Renewable energy
Wind, wave, tidal geothermal, biomass and solar energy are renewable, these are natural sources of energy that are non finite and can be quickly replenished
Describe the process of Wind power
The wind turns a propeller-like blades on the rotor, this is connected to a generator which creates the electricity
Advantages of wind power
Wind energy is very cost effective, it is clean and sustainable and renewable
Disadvantages of wind power
Wind energy can be unpredictable and wind farms affect the visual appearance of the landscape
Tidal power
The move to of water turns under waters turbines which drive generators
Advantages of tidal power
A constant, predictable, renewable energy source which is clean
Disadvantages of tidal power
Expensive to set us and maintain
Solar panels advantages
Renewable, clean power, no greenhouse gases, Energy can be collected on sunny or cloudy days
Solar panels disadvantages
Energy generation levels are lower in winter months when daylight hours are shorter
Biomass energy
Is organic matter that can be extracted by burning or anaerobic digestion, which creates a biogas and a biofetilliser
Biomasss advantages
A renewable form of energy with a plentiful supply of material, carbon neutral
Biomass disadvantages
Risk of deforestation, if trees are not replanted increase in CO2 emissions
Hydroelectric Power
A turbine converts this kinetic energy into mechanical energy, and a generator turn this into electricity.
Hydroelectric Power advantages
Hydroelectric energy is renewable, reliable and does not pollute, it can be regulated according to demand
Hydroelectric power Disadvantages
The cost and environmetal pollution of dam construction is very high, it impacts on surrounding water flow and affects ecosystems
Batteries
Batteries contain chemicals that are toxic and should be disposed of correctly at a recycling centre. If the batteries end up in a landfill, the chemicals can contaminate the ground causing the soil or water pollution, harming the environment
Alkaline Battery
Have a high energy capacity and long shelf life, the power output gradually decreases
Rechargeable battery
Ca be charged many times, the power output remains constant until they run flat, they have 12 volts per cell
Modern Materials - Developed or discovered since WW2 - 1945
Modern materials are developed with enhanced properties through the invention of new or improved processes
Graphene
Graphene is a single layer of carbon atoms, it is the thinnest known material to date, extremely strong, light and conductive to hear and electricity
Metal foam
Metals foams contain gas filled pores with good stiffness to weight ratio, they have good heat resistance and sound absorption
Liquid crystal display - calculator
Contains a matrix of pixels and a backlight
Nanomaterials
A very small scale, less than 100 nanometers in size, Nanotechnology adds properties to products, such as tensile strength and rigidity, they are resistant to bacteria, super hydrophobic, repel dirt and neutralise bad odours
Titanium
It has a high strength, is lightweight and resists corrosion, it reacts with human tissue so is used in medicine for artificial joints
Coated Metals
An unprotected ferrous metal is liable to rust and corrosion due to exposure to the environment. Examples include galvanised steel, plastic coatings such as Teflon, anodising, thermoplastic dip coating and painting
Smart materials
All smart materials are orders but not all modern materials are smart
Polymorph
Is a polymer that can be shaped and reshaped many times, when warmed to 62 degrees, the polymorph becomes flexible and easy to mould into the desired shape. It becomes stiff and strong, used for entomological handles
Thermochromic materials
Thermochromic materials change Color t certain ranges of temperature
Photochromic materials
Photochromic pigments change colour when exposed to different UV levels
Composite materials
A composite material is composed of at least two materials, when combined the properties are superior to those of the individual components
Glass reinforced plastic
Is a polyester, reinforced with the addition of glass fibre, it is produced by combining thermosetting polyester and lightweight composite
Cargo fibre reinforced plastic
IS a thermoplastic reinforced with carbon, it has a high strength to weight ratio and is very rigid
Technical Textiles
They can be coated, laminated or impregnated to improve the properties and performance
Gore-tex
breathable yet waterproof used for outdoor clothing
Kevlar
Is a plastic fibre with high tensile strength it is heat resistant and extremely hard wearing, flexible and lightweight. It is a lightly woven cloth that sits cut, puncture and ballistic resistant, used to make body armour and bulletproof vests, if a projectile hits the Kevlar the fibres ‘catch it’ absorbing and dissipating its energy. It’s used to reinforce tyres add strength and durability to sports equipment
Microfibres
Micro-encapsulation is a process of adding a coating to tiny particles or droplets
Fire resistant fabrics
They withstand heat and resist burning, heat and flame resistant fabrics such as Kevlar and Nomex, provide protection against flame without melting or dripping. Nomex is exposed to heat, its fibres thicken and absorb heat energy
Conductive fabrics
They are coated or blended with conductive metals for thermal heating, they can have batteries, smalll lights and electronics embedded into them,
Systems approach to designing
A system comprises parts or components that work together to control a task or activity
Light Dependent resistor
Resistance increases in the dark and decreases in the light (INPUT)
Pressure Sensor
Detects changes in pressure in gases or liquids, also used to detect weight (INPUT)
Temperature Sensor
When the temperature increase resistance decreases (INPUT)
Resistor
Limits the flow of current (PROCESS)
Microcontroller
A programmable component (PROCESS)
Microcontroller, Processes, for programming microcontrollers
They can perform the task of multiple ICs, they can be programmed in a variety of computer languages or software that uses flowcharts for programming
Timers and counters
Microcontrollers can be programmed for decision making with counting and timing functions
Outputs
Buzzer, Light emitting diode, lamp, speaker
Mechanical devices
Mechanical device can change one form of force to another. An input motion transforms into force to make an output motion
Linear motion
Movement in one direction along a straight line, eg. Train
Reciprocating
This is repetitive up and down or back and forth linear motion, eg. Sewing needle
Rotary motion
Movement on or around an axis, eg. Gears
Oscillating
Movement is backwards and forwards along a curved path, eg. Swing
Mechanical advantages formula
MA=Load/Effort
First order lever
First class levers have the fulcrum between the force and the load, eg. Pliers
Second class levers
Second orders levers have the fulcrum at one end with the effort at the opposite. Eg. Wheelbarrow
Third order lever
Has the fulcrum at one ed, the load at the other and the effort applied in the middle, eg. Tweezers
Bell crank
The bell crank linkage changes the direction of the input motion through 90 degrees
Gears
Gears are toothed wheels, that mesh to transfer motion from one part of a machine to another
Drive gear
The drive gear turns the driven gear. The gears turn in opposite directions. The toothed wheels interlock to prevent slipping
Idler gear
Turns in the same direction as the drive gears, size dos not affect speed
Calculating gear ratio
Number of teeth on driven/number of teeth on drive
Velocity ratio
Rotations of the drive gear/rotations of the driven gear
Pulleys
In machines, pulleys transmit rotary motion and force from the input or drive shaft to the output or driven shaft
Belts
Often made of Kevlar, a lop of flexible rubber connects to or more pulleys
