Chap 2 Flashcards
What is the formula for Density
Mass/Volume
What is the S.I. unit for density?
kg/m cube
How do you define the strength of a material?
The ability of a material to withstand an applied load without breaking or tearing
How do you define the hardness of a material
The ability to scratch another material
Why is a cooking pot made of aluminium whilst its handle is made of plastic?
Aluminium is a good heat conductor but plastic is not
What is the hardest mineral such that it is used in drill bits to cut rocks
Diamond
Electrical wires are made of ________ which is a good electrical conductor and the outside covering on the wires is made of ________ which is a poor electrical conductor
Copper
Plastic
The bulb is made of ______ to allow _______ to pass through and radiated in all directions
Glass
Light
The filament is made of tungsten which has a high _______ point, to withstand the high ________
melting
temperature
The stem is made of glass and the cap is filled with ________ insulation to prevent the conduction of _______.
ceramic
electricity
The bulb is filled with _______ gas to prevent the filament wire to be ________ off
inert
burnt
Define independent variable
The independent variable is the factor that will affect the result of the experiment
Define dependable variable
The dependent variable is the factor that will affected by the independent variable
Define controlled variables
The controlled variables are the factors that are kept constant
What plastics are strong but not tough, brittle and cannot be stretched without breaking
Rigid Plastcis
Define flexible plastics
Flexible plastics can be stretched easily, not strong but tough
To float on water, the submarine forces the water out of the main ballast tank. The ______ of the submarine _______ when it fills its main ballast tank with water and _______ when it forces water out of its main ballast tank
density
increases
decreases
What temperature is water most dense at?
4 degrees Celsius
Why does recycling paper help reduce the level of carbon dioxide in the atmosphere?
There are more trees to decrease the amount of carbon dioxide through photosynthesis
What material is a poor conductor of heat, not transparent, not brittle and not made by weaving materials together Metals Plastics Ceramics Glass Fibre
Plastic
What material is a poor conductor of heat, not transparent, but brittle Metals Plastics Ceramics Glass Fibre
Ceramics
What material is a poor conductor of heat and transparent Metals Plastics Ceramics Glass Fibre
Glass
What material is a good conductor of heat Metals Plastics Ceramics Glass Fibre
Metals
State 4 characteristics of chalk
Permeable
less dense than water
Splits when hit by hard objects
Wears off when undergoing friction
