GCSE DT Unit 2

List types of energy store

pneumatics, hydraulics, kinetic pumped storage, flywheels, batteries

List the uses of titanium

jewellery, watches, joint and dental implants, aircraft, spacecraft, sports car parts

Why do fibre optics transfer data so fast?

They carry information as light

State some properties of graphene

highly conductive, flexible, stretchable, good strength-to-weight ratio, impermeable

What does LQD stand for?

Liquid crystal display

How thick are nanomaterials?

Between 1-1000 nanometers

Which material would be best for lightweight impact bearing, out of polymorph, titanium, and metal foams?

metal foams

What degree Celsius is polymorph mouldable at?

62

What is a smart material?

One which can react with an external stimulus

What is the difference between photo- and thermochromic pigments?

Photochromic pigments change colour with light, but thermochromic pigments change colour with heat

When will a shape-memory alloy return to its remembered shape?

When given thermal or electrical energy

What is contained in the small pods in self-healing materials?

Resin or bacteria

What can QTC be used for?

touch sensitive interactive devices, speed controllers, wearable technology

Which material produces electricity when stressed but moves when given electrical energy?

Piezoelectric material

Why does Litmus paper change colour in substances with different pHs?

Lichen dyes

What is a composite material?

One which has been formed from two or more materials are combined

What two materials are used to reinforce plastic?

Glass and carbon fibre

How does Gore-Tex keep water out but let vapour through?

It is a membrane with many tiny pores

List properties of Kevlar making it useful for bulletproof vests

Excellent cut and tear resistance, hard-wearing, high tensile strength

What are conductive fabrics?

Fabrics which allow an electric current to pass through them

How do fire resistant fabrics resist flame?

They produce a chemical reaction that slows ignition

How thick are microfibres?

Less than 1 denier

What are microencapsulated materials used for?

Anti-bacterial, heat-regulating or insect repellent clothing

What is a mechanical device?

Machines or tools that use different parts to manipulate energy to perform tasks

What are the two parts of a lever?

The bar and the fulcrum

How is MA calculated?

Load / effort

What is equilibrium in terms of levers?

when load and effort are equal

What lever class is similar to a seesaw?

First order

What lever class is similar to a wheelbarrow?

Second order

What lever class is similar to tweezers?

Third order

What is a linkage?

A mechanism made by connecting rigid moving parts through pivots

What is a rotary system?

A mechanism used too change the direction of force

List the types of cam

eccentric, pear, snail, heart

List the types of followers

flat, knife edged, roller

How is gear ratio calculated?

driven gear's turns / drive gear's turns

Why are drive belts often made from rubber?

It provides the best friction

What is a block and tackle?

A system of two or more pulleys that can be used together to reduce effort required to lift or move a heavy load

What are the two classes of energy?

renewable and non-renewable

List all renewable energy sources

wind, solar, tidal, hydroelectric, biofuel, nuclear

List all non-renewable energy sources

coal, gas, oil

What spins a generator in order to produce electrical energy?

Turbines

List types of potential energy

chemical, mechanical, nuclear, gravitational

List types of kinetic energy

movement, electricity, thermal, sound, light

Where do plastics get their name?

Their shared property of plasticity

Name two types of corn starch polymer

PLA, Biopol

What is MDF used for?

creating curved forms out of wood-textured material