Tech Exam 24 Nov Flashcards
(85 cards)
1
Q
What is recycling
A
Recycling is the process of converting waste materials into new materials and objects. The recyclability of a material depends on its ability to reacquire the properties it had in its original state.
2
Q
What two categories can you sort metals into
A
Iron and non-iron metals
3
Q
What is a ferrous metal
A
Ferrous metal is a metal that contains iron
4
Q
What does the iron content cause the ferrous metal to do
A
The iron content in the metal causes ferrous metal to corrode easily.
5
Q
What is a non-ferrous metal
A
Non-ferrous metal is a metal that doesn’t contain iron (examples: aluminum, copper, lead, zinc and tin, as well as precious metals like gold and silver).
6
Q
Name some non-ferrous metals
A
aluminum copper lead zinc tin as well as precious metals like gold and silver
7
Q
Name some ferrous metals
A
alloy steel
carbon steel
cast iron
and wrought iron
8
Q
What can be recycled at school
A
Paper: such as newspapers, magazines, used writing paper.
Glass: such as empty glass bottles and jars.
Plastic: such as empty plastic bottles, other containers, plastic bags and old pen casings.
Metal: such as metal lids of bottles and jars, empty cans and tins.
9
Q
True or false
Batteries, light bulbs, and ink cartridges must NOT be recycled separately.
A
False
10
Q
Define reduce
A
Reducing the amount of waste that is created by buying fewer plastics or items with less packaging than buying items with more packaging. For example, you can buy food with one packaging than those with two or more packaging.
11
Q
Define Recycle
A
using an item again by breaking the item down into a more basic substance and reformed into something new. Eg. newspapers should have been recycled into paper bags etc.
12
Q
Define Reuse
A
Reusing an item instead of throwing it away. Eg. an ice-cream bakkie can be used as a lunchbox or storage container instead of throwing them away.
13
Q
Define Renew
A
renewing an old item so that it looks like new items. For example adding a new coat of paint or vanish on a desk will make it look new rather than throwing it away.
14
Q
Define Repair
A
Repairing old products rather than throwing them away or replacing them. This saves money and reduces waste on the landfills. For example you can repair an old broken cupboard rather than buying a new cupboard.
15
Q
What are the 5 Rs ( for recycling)
A
Reuse Reduce Recycle Renew Repair
16
Q
Go through the answers for the activities for recycling
A
Both activities
17
Q
Why are mechanisms useful
A
They help us to move things further, faster, or more easily. They can also change the direction of movement.
18
Q
What is mechanical advantage
A
Mechanical advantage is the ability of a mechanism to make work easier. It reduces the input or effort force so that the load is easier to move.
19
Q
What are the 6 simple mechanisms
A
1) Lever
2) Wheel and axle
3) Screw
4) Inclined Plane
5) Wedge
6) Pulley
20
Q
How do you use a pulley
A
You pull the rope and the rope slides on the pulley, turning the wheel and the load is lifted. The pulley makes it possible to change the direction in which the rope pulls.
21
Q
What do pulley systems do
A
Pulley systems make it easier to lift a load.
22
Q
Two pulleys connected to a single piece of rope will give
A
mechanical advantage.
23
Q
A crank is an adaptation of a …………………..
A
Second class lever
24
Q
How does a crank work
A
A crank consists of a handle or arm attached at a right angle to a shaft. A crank increases mechanical advantage by increasing the distance between the handle and central shaft. This makes turning easier.
25
What is a Winch
A machine that lifts heavy objects by turning a chain or rope around a tube-shaped drum. Typically turned by a crank or by a motor.
26
Give 2 examples of when a crank is used
Carjack
Fishing rod
Eggbeater
bicycle pedals
27
Look at the Earths magnetic field in notes
This is why a compass needle points in an N/S direction.
28
All magnets have a ....................... Sometimes these poles are painted in different colors to assist us.
North and a South Pole.
29
What is a permanent magnet
These magnets retain their magnetism for an indefinite period of time.
30
What is a temporary magnet
These magnets lose their magnetism over a period of time.
31
True or false
| Permanent magnets CAN be any shape and size
True
32
Groups of particles, from which a magnetic material is made, form tiny regions, What are they called
form tiny regions called domains.
33
How do you know if something is magnetized
Once the domains have been arranged in the same direction, the material is magnetized and serves as a magnet.
34
How can you magnetize a ferrous metal
Ferrous metal, that is not magnetized, can be magnetized by drawing it over a magnet.
35
How do you un magnetize a ferrous metal
When you draw the metal over the magnet in the opposite direction this will reverse the process.
36
What is a strip magnet
Magnetic material is mixed with plastic to form strip magnets. These magnets can easily be cut into different shapes as indicated below:
37
Look at the repulsion and attraction of magnets (pictures)
All the pictures
38
What is a circuit
A circuit is the path that an electric current travels on
39
How many components does a simple circuit contain
a simple circuit contains three components necessary to have a functioning electric circuit. Circuits are driven by flows.
40
What is a component
A component is one part of a whole system.
41
What 3 things does an electric circuit need
An energy source. This can be a cell or a stronger power source.
A complete circuit. There has to be an unbroken pathway of conducting materials through which the electrical current can flow.
A load. There has to be some form of resistance in the circuit. This could be in the form of a light bulb, a resistor, a motor or other electrical components.
42
Remember all symbols
In electric circuits
43
What is a battery
A battery is made up of one or more cells.
44
A battery with one cell is often referred to as a
A battery with one cell is often referred to as a ‘single-cell battery‘.
45
Remember
When there is more than one cell, they are connected together internally in series, but from the outside they usually look like a single item (one positive and one negative terminal).
46
If batteries are parallel what happens
Parallel: The voltage remains the same, but the power is increased. This means that the batteries would last longer.
47
What is an electromagnet
Electromagnets are magnets that are created using electricity. They are not permanent magnets. They are only magnets when electricity flows through conducting wire that is coiled around them. When the electricity is switched off, they lose their magnetism.
48
What is magnetism
Magnetism is the force that pulls (attracts) or pushes (repels) an object which contains metal towards, or away from, a magnet.
49
What is a permanent magnet
A permanent magnet keeps its magnetic properties for a long time(indefinite period).
50
What is scrap metal
Scrap metal is waste metal or used articles made of metal, often collected and reprocessed.
51
What are electromagnets used for
Electromagnets are very useful for separating scrap material. Scrap material in waste dumps is usually a mixture of metals and non-metals. The ferrous metals, which are those that contain iron, are still valuable. It takes a lot of time to sort waste material by hand.
52
What are ferrous metals
Ferrous metals (metals containing iron) are attracted to magnets. An electromagnet is passed through the waste material and all the ferrous metals stick to it. The electromagnet is then moved over a collection bin. When the electromagnet is switched off, the ferrous metals are no longer attracted to it and they fall into the bin.
53
Give 2 examples of when electromagnets are used in devices
1) motors: to rotate the motor,
2) loudspeakers: an electromagnet responds to the sound signals and amplifies them,
3) computer hard drives: electromagnetism is used to write and store data,
4) electric bells: electromagnets attract and release the hammer of the bell,
5) a magnetic door switch: electromagnets can close and open doors.
54
How does an electromagnet work?
There is a strong relationship between electricity and magnetism. The electricity in the wire coils (solenoid) creates a magnetic field. The iron nail is right in the middle of this magnetic field. Because the iron nail is a magnetic material, it becomes magnetised by the field. The magnetic field from the electric current is made much larger, or amplified, by the magnetic field in the iron nail. Without the iron core, the magnetic field would be very weak. When the electric current is switched off, the iron nail loses its magnetism.
55
How does an electric motor work
There is an electric circuit (armature) between two magnets.
When the electric current passes through the circuit, the electromagnetic field causes it to be repelled upwards and downwards, on either side, by the two magnets.
As the armature turns, there is a break in the electric current.
It then reconnects and repels the circuit once again.
This continues over and over again.
56
What is a refugee
REFUGEES are people who are forced to leave their homes during a disaster or in an emergency.
Sometimes, refugees move to a safe area that is close by, and at other times, they have to travel to another country.
57
What do people need
People need shelter, water and food.
58
What does an emergency situation effect
Emergency situations can cause large numbers of people to be forced from their homes. Emergencies not only affect people in areas where a disaster took place, but also the people in the area where the refugees are moved to.
59
True or false
A refugee camp has to be set up, and the camp doesn't have to be well planned
False
A refugee camp has to be set up, and the camp needs to be very well planned.
60
What are the two types of emergency situations
Two types of emergency situations that force people to leave their homes are war and natural disasters.
61
What do wars do to people
Since the beginning of time, there have been wars between people all over the world, and while armies fight battles, people are forced to flee from their towns and villages.
62
How many refugees are there in Africa
Even today, there are more than 3,8 million refugees all over Africa. These people have been chased from their homes because of wars.
63
What are natural disasters
Natural disasters are caused by nature and not by people. All of them can force people to leave their homes. Natural disasters usually happen with no warning. They can create emergencies very quickly, which means that people must move to safer areas immediately.
64
Droughts can create emergencies for farmers.
During long droughts, large groups of people can be forced to leave their homes and their farms.
What do these people look for
These people then look for food, water and shelter, and they become refugees.
65
What are emergencies that happen slower or over long periods of time
Emergencies that happen more slowly over longer periods of time include droughts or long wars
66
Are there mixes of people in refugee camps
Yes
The type of emergency situation influences the mix of people in a refugee camp.
67
When are there are usually fewer men at home,
During a war, there are usually fewer men at home, because the men will be fighting.
68
What do elderly people need more
Old people need more warmth and blankets.
69
What do children need more of in emergency situations
Children become dehydrated more quickly than adults do, and they also need more high-energy foods.
70
Why do babies and elderly people die easier in emergencies
During a drought, babies and elderly people may die since they are more vulnerable.
71
What are refugee shelters
Refugee shelters are structures ranging from the most temporary tent accommodation to transitional shelters to building temporary settlements and including the most basic kind of ad hoc structure.
72
What is an emergency
Dangerous situations such as fires, floods and accidents usually happen unexpectedly. People need to take immediate action to save the lives of the people involved.
73
Do emergencies always mean that many people are forced away from their homes
Emergencies don’t always mean that many people are forced away from their homes. An emergency may affect only one family or even just one person.
74
What are People who work in emergency services are called
People who work in emergency services are called emergency workers.
75
What does PPE stand for
Emergency workers wear clothes that are designed to protect them from danger. These clothes are known as personal protective equipment or PPE.
76
What are The materials we use to make any kind of clothing called
The materials we use to make any kind of clothing are called “textiles”.
77
What are special textiles made from
Special textiles are used to make protective clothing. These textiles are made from woven or knitted materials, that can have chemicals added to them to give them special qualities, such as waterproofing or fire resistance.
78
WHat are the special textiles and explain
Textiles and materials used to manufacture emergency worker clothes
Kevlar is a textile that is stronger and lighter than steel. Kevlar fibres are strong and are difficult to break. It is
also water-resistant.
Nomex is a material that is resistant to heat, flames and chemicals. It gets added to other textiles and prevents
them from melting in temperatures up to 370 degrees °C.
Rubber is a strong, waterproof, elastic substance made from the sap of the rubber tree. It can also be
produced chemically, by using petroleum by-products. It is used for making tyres, boots, and other products.
Nylon is a synthetic fabric. It is lightweight, strong and relatively waterproof. It
can be made more waterproof by rubbing it with wax.
Teflon is a material that prevents things from sticking to it. It repels water and can be
used as a waterproofing material.
PVC is a plastic material that is used for many purposes, for example, to make
clothing or shoes. It is a waterproofing material. PVC stands for polyvinyl chloride.
Neoprene is a type of synthetic rubber that is flexible and elastic. It is waterproof and wind-resistant.
79
List the protective properties of firefighters gear
Firefighters need protection from flames and heat. The clothes they wear must also still allow for movement. Both the jacket and pants have 3 layers.
• The outer layer is made of Kevlar, which is fire-resistant.
• The middle layer is made of Nomex, which protects the firefighter from the heat of the fire.
• The inner layer consists of a moisture barrier that keeps the firefighter dry.
There are reflective strips on their clothing, so that they can be seen in the smoke. They also wear helmets, heat-resistant gloves and hoods made from Nomex. Their boots are heat resistant, oil resistant, slip resistant, chemical resistant, flame resistant and made of waterproof material. They are reinforced with steel to protect their feet from falling objects.
80
List the protective properties of Sea rescue workers gear
Sea-rescue workers need protection from water, rain, the wind and cold. Their outer layer of clothing must be completely waterproof. This type of clothing is covered with waterproofing materials such as PVC (plastic), rubber or Teflon.
Divers and rescue swimmers will wear wetsuits. Wetsuits are made from a textile called Neoprene. It’s a good insulator of heat and therefore the rescuer will not lose body heat. Wetsuits allows a thin layer of water to be trapped between a person’s body and the wetsuit. This layer of water is heated by the person’s body and keeps the diver or rescue swimmer warm.
81
The type of food refugees eat depends on the mix of the group.
What do:
Children need more of
Old people need more of
Children need more protein than older people, babies need special milk formulas, and old people need lots of vegetables to protect them from disease.
82
What does the food given in emergency situations need to be
The food has to be
• cheap,
• easy to find
• and it must it must be nutritious
83
Remember
Refugees do not expect expensive food, just enough healthy food. Poor nutrition can lead to problems like illness and disease. If refugees get weak or sick, they will not be able to look after themselves and the situation in the refugee camp will become worse.
84
How do you remain healthy
To remain healthy, the human body needs different types of food, from all the food groups. Diets that contain food from all the food groups are called balanced diets.
85
What food group does a balanced meal include
« Carbohydrates: These provide energy and are found in starchy foods like potatoes, mealie
meal, rice and bread.
« Protein: These build muscle and give us strength. Protein-rich foods include meat, fish,
chicken, eggs, beans, cheese and milk.
« Fats and oils: These provide energy and help to protect our internal organs. They also help
our bodies to fight disease. Foods in this food group include cheese, butter, margarine and
oils such as sunflower or canola oil.
« Vitamins and minerals: These are found in all foods, but especially in fresh fruit and
vegetables: They-are-very-important for good-health; strong-bones-and-teeth;-and to keep
your brain working well. Vitamins also help to prevent disease. For excmplé, Vitamin C, which
is found in oranges and lemons, fights colds and flu.
