Tech Exam 24 Nov Flashcards
What is recycling
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.
What two categories can you sort metals into
Iron and non-iron metals
What is a ferrous metal
Ferrous metal is a metal that contains iron
What does the iron content cause the ferrous metal to do
The iron content in the metal causes ferrous metal to corrode easily.
What is a non-ferrous metal
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).
Name some non-ferrous metals
aluminum copper lead zinc tin as well as precious metals like gold and silver
Name some ferrous metals
alloy steel
carbon steel
cast iron
and wrought iron
What can be recycled at school
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.
True or false
Batteries, light bulbs, and ink cartridges must NOT be recycled separately.
False
Define reduce
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.
Define Recycle
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.
Define Reuse
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.
Define Renew
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.
Define Repair
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.
What are the 5 Rs ( for recycling)
Reuse Reduce Recycle Renew Repair
Go through the answers for the activities for recycling
Both activities
Why are mechanisms useful
They help us to move things further, faster, or more easily. They can also change the direction of movement.
What is mechanical advantage
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.
What are the 6 simple mechanisms
1) Lever
2) Wheel and axle
3) Screw
4) Inclined Plane
5) Wedge
6) Pulley
How do you use a pulley
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.
What do pulley systems do
Pulley systems make it easier to lift a load.
Two pulleys connected to a single piece of rope will give
mechanical advantage.
A crank is an adaptation of a …………………..
Second class lever
How does a crank work
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.
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.
Give 2 examples of when a crank is used
Carjack
Fishing rod
Eggbeater
bicycle pedals
Look at the Earths magnetic field in notes
This is why a compass needle points in an N/S direction.
All magnets have a ………………….. Sometimes these poles are painted in different colors to assist us.
North and a South Pole.
What is a permanent magnet
These magnets retain their magnetism for an indefinite period of time.
What is a temporary magnet
These magnets lose their magnetism over a period of time.
True or false
Permanent magnets CAN be any shape and size
True
Groups of particles, from which a magnetic material is made, form tiny regions, What are they called
form tiny regions called domains.
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.
How can you magnetize a ferrous metal
Ferrous metal, that is not magnetized, can be magnetized by drawing it over a magnet.