Solids, Liquids, Gases Flashcards
why are liquids and gases fluids
Liquids and gases are both fluids - this is because both of them can flow
what happens as you go from solid to gas to the particles
As you go from solids to liquids, the energy/speed with which the particles move increases, and the density decreases
what is the equation for density
density = mass/volume
density, p (rounded p)
what are the units for density
The unit for density depends on the units of mass and volume - just put those in so a cube of 50 grams and vol of 500 metres^3 would be “ X “g/m^3
describe the particles in a solid
SOLIDS: the particles are regularly arranged in a tightly fixed shape
particles dont move freely and touch eachother
Vibrate around a fixed point
describe the particles in a liquid
Liquids: the particles can move freely however are not fixed in shape and still touch eachother
what is the equation for pressure
Pa = f/a
pressure = force / area
why does a needle poke a fabric rather than a lego brikc
The needle pokes a hole through the fabric because the needle and the lego brick exerts the same amount of force however the needle exerts the force on a smaller area than the lego brick and since pressure is inversly proprotional to area then te needle exerts more pressure, puncturing the fabric
where is high pressure useful
High pressure is useful with cutting tools so these must have a small area
Low pressure is useful to stop camels sinking in sand, so large area is needed, which is why their feet have a large area
how does pressure act in all directions
As long as a liquid is not moving, pressure acts equally in all directions
This is seen if a filled can/bottle is poked with holes, the water is forced out equally in all directions
why dont we feel the pressure for air on our bodies
Why don’t feel the pressure of air on our body: As the pressure inside our bodies is similar, so we don’t feel the pressure of the air
how to work out mass of water in a container
Volume, mass DENSITY
To work out the mass in a container of water, you can use volume (calculate using dimensions) and density (given)
W=mg (equation for weight - g=9.81)
The force (weight) experienced by the bottom surface of the container full of water can be calculated by:
how can u derive the equation for pressure, including density
p = F/A
= volume x density x gravitation field strength / A
since weight = mass x GFS and mass = v x p
(base x width x height) x density x GFS / Area
(Area x height) X density x GFS/ AREA
so
pressure = height x density x GFS
what is naphthalene and its melting point
Naphthalene is the compound they use to make moth balls
It has a melting point of 80degrees
when heating a solid, why does the graph plateu for a while at the melting point
the graph plateus as the heat energy is no longer used for heat, rather used energy to make the perticles expand and vibrate
what is boyls law
absolute pressure of an ideal gas is inversely proportional to its volume under conditions of constant mass and temperature
what is the equation change in pressure
P1xV1=P2xV2
what is abolsute zero
Absolute zero is the temperature at which pressure is 0 - this value is -273 degrees celsius, which is 0 Kelvins.
what is theta
Theta is used as a symbol for temperature when its unit is degrees celsius
what symbol must you use for temperature if the unit is kelvin
When the unit is Kelvin, you MUST use T as the symbol for temperature
what is the equation relating temperature and pressure
p1/T1=p2/T2
in what condition can you only use P1/T1 = P2/T2
When the mass and volume of a gas is constant
why is temperature and pressure directly proportional
temperatuer is directly proportional to pressure because when temperature increases, the particles in the container gain more kinetic energy, moving faster, and there are also move frequent collisions with more force against the container wall. This means the pressure rises aswell
what must the unit be for temperature when using the equation P1/T1=P2/T2
For this equation, the unit of temperature must always be KELVIN
