Chapter 2 - part 2

Question 1

What is a composite material?

Answer 1

2 or more materials combined together to create a new material with improved functionality and properties ( enhanced material)

Question 2

Glass reinforced plastic

GRP

Answer 2

Appearance- Covered with a smooth plastic resin, Easily coloured and moulded
Characteristics- Lightweight, good strength to weight ratio, heat+ chemical resistance
Uses- Helmets, Pipes, Liquid storage tanks

Question 3

Carbon- fibre reinforced plastic

CRP

Answer 3

Appearance- a cloth woven from individual strands
Characteristics- very expensive, stiff rigid
Uses- Musical instruments, Sports equipment, Musical instruments

Question 4

What is a technical textile?

Answer 4

Textile that has been developed with enhanced properties to withstand specific uses

Question 5

Gore tex

Answer 5

• A waterproof and breathable material
• Material helps reduce build up of condensation inside jackets or boots
• It’s a very thin membrane sandwiched between a liner and outer material
  Uses- Outdoor clothing

Question 6

Kevlar

Poly-paraphenyoene terephthalamide

Answer 6

• Non flammable
• Extremely strong+tear resistance
  Uses- bullet proof vests, personal armour

Question 7

What are conductive fabrics?

Answer 7

• aka e-textiles
• allow an electrical impulse to pass through them
• A silvery fabric or thread, can be sewn
• Helps link electrical components together
  Uses- Bluetooth connectivity, electronic sports equipment, anti-static clothing

Question 8

Fire resistant fabric

Answer 8

• E.g Kevlar and Normex
• Made from armed fibres
• Can be dyed a range of colours
• Heat resistance + naked flame(protects wearer)
  Uses- Aprons, Fire blankets

Question 9

What are Microfibres?

Answer 9

They are group of synthetic fibres that are less than one dernier thick

Question 10

What is Microencapsulation?

Answer 10

• Thin fibres that are used to hold chemicals in tiny capsules
• Break open releasing chemicals

Question 11

Microfibres+ Microencapuslation

Answer 11

• Fine synthetic fibre woven into different products
• Can be absorbent but fast drying
  Uses- Medical textiles, Clothing that is anti bacterial, towels

Question 12

What does a system consist of?

Answer 12

Inputs, processes and outputs

Question 13

What is a system diagram?

Answer 13

A diagram that breaks down the operation into 3 main components: Inputs, process and outputs

Question 14

What is an open loop system?

Answer 14

• A system that has no feedback
• It’s unable to make a decision
• Input directly controls the output

Question 15

What is a closed loop system?

Answer 15

It’s able to make decisions using feedback, usually from a sensor

Question 16

Some electronic products have a polarity. What does that mean?

Answer 16

They have a positive and negative side to them, therefore it matters which way around they go in a circuit

Question 17

Toggle switch

Answer 17

Input component

Uses- Lighting

Question 18

Push to make switch (PTM)

Normally open

Answer 18

Input process

Uses-door bells, keyboard

Question 19

Push to break switch

Normally closed

Answer 19

Input component

Uses- Alarm systems

Question 20

Light dependant resistor

LDR

Answer 20

Input component

Uses- Street light

Question 21

Thermistor

Answer 21

Input component

Uses- Thermostats

Question 22

Pressure switch

Answer 22

Input component

Uses- Burglar alarms

Question 23

Light emitting diode

LED

Answer 23

Output component

Uses- Torches, Tv screens

Question 24

Lamp

Answer 24

Output component

Uses- Car headlamps, floodlights

Question 25

Buzzer

Answer 25

Output component | Uses- Alarm system, electronic games

Question 26

Speaker

Answer 26

Output component | Uses- Headphones, radios

Question 27

What are integrated circuits?

Answer 27

They are used to form multiple tasks. Most common one is a microcontroller

Question 28

What is an analogue signal?

Answer 28

It’s a continuous signal with an infinite range of values

Question 29

What is a digital signal?

Answer 29

It’s either on or off

Question 30

What is a monostable device?

Answer 30

- Aka a single shot timer | - it’s only stable in the off position

Question 31

What is an astable device?

Answer 31

- Gives an oscillating output

Question 32

What are counting devices?

Answer 32

They are used to keep a tally of how many times and event occurs

Question 33

Linear movement

Answer 33

Movement in one direction along a straight line

Question 34

Reciprocating motion

Answer 34

Repetitive up and down motion

Question 35

Oscillating material

Answer 35

Similar to reciprocating but it’s in a curved motion

Question 36

Rotary motion

Answer 36

A circular motion

Question 37

What is a lever?

Answer 37

A simple way to gain mechanical advantage

Question 38

What is equilibrium?

Answer 38

When the effort and load are equal

Question 39

Class 1 lever

Answer 39

- Fulcrum in the middle | - Load and effort on the opposite ends

Question 40

Class 2 lever

Answer 40

- Fulcrum on the side - Load next to the fulcrum - Effort next to the load

Question 41

Class 3 lever

Answer 41

- Fulcrum is on the side - Effort is near the fulcrum - Load is next to the effort

Question 42

Reverse motion linkage

Answer 42

Changes the direction of input so that the output is in the opposite direction

Question 43

Parallel motion or push/pull linkage

Answer 43

Input and output travel in the same direction. Uses 3 linking bars

Question 44

Bell crank linkage

Answer 44

Changes the direction of Input through a 90 angle

Question 45

Crank and slider

Answer 45

Changes rotary motion into reciprocating motion and vice versa

Question 46

Treadle linkage

Answer 46

Changes rotary motion into oscillating motion or vice versa

Question 47

What is a cam used for?

Answer 47

To change rotary motion into reciprocating motion using a follower

Question 48

Eccentric or circular cam

Answer 48

Steady rise and fall

Question 49

Pear cam

Answer 49

Rapid rise and fall

Question 50

Snail cam

Answer 50

Steady rise and sudden drop

Question 51

Heart shaped cam

Answer 51

Slight rise and fall

Question 52

Flat follower

Answer 52

Not very accurate, lots of friction, can cope well under load

Question 53

Knife edged follower

Answer 53

Tracks movement of cam accurately, low friction

Question 54

Roller follower

Answer 54

Some accuracy, Efficient under load

Question 55

Block and tackle

Answer 55

2 or more pulleys used to reduce the effort required to lift or move a heavy load