Unit 2 - Energy, Materials, Systems and Devices

A well is drilled into crust until it hits shale rock, sending a high-pressure mixture of water, sand and chemicals to release the gas.

As the fossil fuel burns it generates heat, which is used to create steam that drives a turbine to generate electricity.

Stored energy to be released

• The energy an object has due to its motion • Can be transferred

• When there's low demand, surplus energy spins a flywheel • Flywheels maintain momentum due to an almost frictionless environment • If demand rises the momentum is used to drive a generator to feed energy back into the grid

Pneumatic systems rely on a constant supply of compressed air, provided by an air compressor, to produce a force

Hydraulic systems rely on compressed fluid, provided by a pump, to produce a force

They store chemical energy and chemical reactions are used to generate electricity

Biodegradable polymers, break down after use

flexible MDF, can be folded into curved desks etc.

titanium, strong and light

LCDs, compact, light and have low power use

Teflon, creates a non-stick surface and water-proof

polymorph, easy to remould

Energy used in manufacturing and transport comes from vegetable starch that absorb CO2 during growth, which offsets the CO2 released

• Glass-reinforced plastic • Light and strong • Corrosion, chemical and heat resistant

• Carbon fibre • Light and strong • Good tensile strength • Water and chemical proof

• Gore-Tex • Waterproof • Breathable as moisture vapour can escape

• Kevlar • Very strong and hard-wearing • Cut and tear resistant • High thermal protection

• Fire-resistant fabrics • Resist heat and ignition from naked flame

• Microfibres • Absorbent and fast-drying

1. Prepare mold

2. Apply release agent

3. Apply gel coat

4. Apply GRP matting

5. Apply resin and work it evenly into the matting

6. Clamp in position and leave to cure

7. Release mold

8. Trim and finish workpiece

continuous variation with no set scale

signals that are on or off with a set scale

piezoelectric material

Photochromic pigments

QTC and piezoelectric material

QTC, piezoelectric material and shape memory alloy

Thermochromic pigments and shape memory alloy

litmus paper

Piezoelectric material, self-healing polymers

Nitinol - alloy of nickel and titanium

quartz

• When cracks appear water seeps into them rupturing spheres of food and bacteria and activating them • Bacteria begins to feed resulting in calcium carbonate that bonds the concrete and fills the crack

• QTC changes its electrical resistance based on changes in applied force. • The more force applied the lower the resistance

They change shape if voltage is applied

emit sound - output

resistance decreases when light intensity increases - input

emits light when a current passes through it - output

provides a momentary connection - input

provide a temporary disconnection - input

produces an audio signal - output

resistance decreases when temperature increases - input

latches on a connection - input

A system that does not respond to changing conditions

Uses feedback built into the device to respond to changing conditions

A signal pulse is triggered by a switch or sensor - used for timing length of an event

Produces a stream of pulses that are oscillating and constant

changes magnitude/direction of a force

axis of rotation (fulcrum) is between the effort (force) and load

load is between the axis of rotation (fulcrum) and the effort (force)

repeated back and forth movement of an object

repetitive linear motion

A gear that allows the driver gear and the driven gear to turn in the same direction

round with hole for offcentred camshaft

long dwell, slow rise, sudden drop

long dwell, rapid rise and fall

designed to have no dwell period

• Pulley wheels have V-shaped grooves for extra friction from larger surface area, as well as to insure the belt is engaged • Belts may have notches for more efficient flexing • Pulleys attach to driver shafts to transfer motion to other parts of the mechanism