Revision Year 9 Notes Flashcards
What are examples of thermoplastics?
Acrylic(Perspex)
Polythene
Polyvinyl chloride(PVC)
What are examples of thermosetting plastics?
Polyurethane
Melamine formaldehyde
Polyester resins
What are the different types of metals?
Ferrous
Non-ferrous
Where does the word ferrous come from?
The Latin word ferrum meaning containing iron
What are ferrous metals?
Contains iron
Usually magnetic
What are non-ferrous metals?
Doesn’t contain iron
Some non-ferrous metals are magnetic but, not usually
What are some common ferrous metals?
Iron
Steel
What are some common non-ferrous metals?
Aluminium
Tin
Copper
Zinc
What are the top 5 most used metals?
Iron Aluminium Copper Zinc Manganese
What are the properties of metals?
They are hard and strong
They are solids at room temperature (Except for Mercury). They have a shiny lustre when polished
They make good conductors of heat
They make good conductors of electricity
They are dense, malleable and ductile
What is a mechanism?
A mechanism is a system of moving parts that performs some function. They are used to reduce the effort in relation to work
What are different types of mechanisms?
Levers and linkages
Wheels
Pulleys
Gears
What are the three basic building blocks of mechanic control?
Input
Process
Output
What is the input?
The input is usually a force and initiates the process.eg. A foot on a pedal
What is the process?
The process will change the magnitude or direction of the force.eg. Mechanisms allow petrol into the engine
What is the output?
The output is what performs the desired task.eg. Car moves
Complete this sentence, a mechanism
Has an input, process and output
Can change the direction in which a force acts
Can change the size of the force
Can change the place where the force acts
What is a lever?
A lever is a type of mechanism, perhaps the earliest form of mechanism
What are the three basic parts of the lever?
Fulcrum
Load
Effort
What are the different types of levers?
Class 1 lever
Class 2 lever
Class 3 lever
What is does a class 1 lever look like? Give an example.
Load Effort
——————————- Eg. Scissors/crowbar
Fulcrum
Or pivot point
What does a class 2 lever look like? Give an example.
Load
———————————– Eg. Wheelbarrow
Fulcrum Effort
Or pivot point
What does a class 3 lever look like? Give an example.
Load
———————————- Eg. Tweezers
Fulcrum Effort
Or pivot point
What is a gear?
Gears are wheels with teeth which mesh to transmit rotary motion. When two or more gears mesh it is called a gear train
