8i Summary Sheet Flashcards
What is a fluid?
Fluids are liquids or gases.
Give two properties of solids
● fixed volume
● fixed shape
Give 2 properties of liquids
● fixed volume
● take shape of container
Give two properties of gases
● expand to fill container
● take shape of container
Which state of matter has the most energy?
Gas particles have the most energy
What states of matter can be poured?
Gas and liquid
What is density?
Density is the mass of a certain volume of something.
What is the formula for density?
Mass
Density=—————
Volume
What are the 2 units for density.
The units for density are g/cm^3 or kg/m^3
What are the 2 units for density.
The units for density are g/cm^3 or kg/m^3
When do substances change state?
Substances can change state when they are heated or cooled.
Does the temperature of a substance change while it is melting?
The temperature of a substance does not change while it is melting, even if it is still being heated.
What happens to substances when they are heated?
Substances expand when they are heated.
Order the states of matter from taking up the most space to the least.
The particles in a solid vibrate more and take up less space. The particles in liquids and gases move around faster and take up more space.
Gas > liquid > Solid
1) Why do substances contract when they cool down?
2) What happens to the volume and density?
1) Substances contract when they cool down, as the particles have less energy and do not move as
much.
2) This reduces the volume and increases the density.
Can fluids flow?
Yes
Can fluids flow?
Yes
What direction does pressure in fluids act?
Pressure in fluids acts in all directions.
Why is there pressure in fluids?
The particles in fluids are moving all the time and hitting the walls of containers and other things they come into contact with. The force of the collisions causes pressure, which acts in all directions.
Give 3 ways pressure of gas in a container can be increased.
● putting more particles into the container (so there will be more collisions with the container
walls each second).
● heating the gas (so the particles move faster, hitting the walls harder and more often).
● reducing the volume of the container (so the particles do not have as far to go between the
walls and so collide with the walls more often).
What happens to the pressure when you go deep in the sea vs high on a mountain?
As you go deeper into the sea, pressure increases because there is more water above you
pressing down. If you climb a high mountain, the air pressure on you will get less, because there is
less air above you pressing down
What does the weight of an object have to be for it to float on water and why.
The density of water is 1 g/cm^3, so objects with densities less than 1 g/cm^3 will float in water.
What is drag?
Drag is another name for air resistance or water resistance.
How can the amount of drag on something be reduced?
The amount of drag on something can be reduced by giving it a smooth surface and a streamlined shape.
How can the amount of drag on something be reduced?
The amount of drag on something can be reduced by giving it a smooth surface and a streamlined shape.
What happens to drag as the speed increases?
The drag increases as the speed increases.
Why do objects moving through air get hot?
The particles transfer energy to the object, which is why objects moving through air can get hot.
