heating, particles, presure Flashcards
equation for density
density= mass / volume
unit of density
g/cm3 or kg/m3
1g/cm3 = 1000kg/m3
what does the average density of an object determine
whether it floats or sinks
if a solid object floats on a liquid what does it mean
means object has lower density than liquid
what does an object sinking mean
object has a higher density than its surroundings
equation for pressure
pressure = Force/ Area
unit of pressure
pascals (Pa) / kilopascals (kPa)
what can 1 Pa be defined as
1 N/m2
how does pressure act in gasses and liquids at rest
pressure at any point acts equally in all directions
in gases + liquids as the depth increases what happens to the pressure
give examples of places of high pressure and place of low
depth increases = pressure increases
eg. pressure is higher at the bottom of the sea then at surface & lower high up in the atmosphere
what is pressure difference
the difference in pressure between 2 points in liquid or a gas
equation for pressure difference
pressure difference= height (depth) x density ( of liquid) x gravitational field strength
what is the unit for pressure difference
Pascals (Pa)
describe particles in a gas
almost no forces of attraction
lots of energy
free to move around
travel in random direction at high speeds
describe particles in a liquid
weak forces
close together but can move past each other
irregular arrangements
move in random directions at low speeds
describe particles in a solid
strong forces
close together
fixed regular arrangement
not much energy= only vibrate around fixed positions
what does heat energy do to particles
particles vibrate faster
forces overcome and particles start to move around
what is the particle theory say about gasses
very small particles
moving in completely random directions
what do particles in a gas do
constantly collide with each other, and with the walls of their container
what happens if you increase the temperature of a gas
you gives its particles more energy
what happens if you double the temp of a gas ( kelvins )
you double the average kinetic energy of the particles
what is the rule for temp of gas and av. kinetic energy of its particles
temp of gas ( in kelvins ) is proportional to the average kinetic energy of its particles
what type of energy does anything moving have
kinetic energy
equation for kinetic energy
1/2 x mass x volume2
what motion supports the particle theory
Brownian motio
what is Brownian motion
particles in liquids + gasses moving randomly.
larger particles can be moved by smaller surrounding particles
what is the coldest temp anything can get
-273 degrees C
what is -273 degrees C aka
absolute zero
how much kinetic energy do atoms have at absolute zero
as little kinetic energy as its possible to get
what is absolute 0 the start of
the kelvin scale
what is the similarities in Kelvin and degrees C
a temp change of 1 degrees C = temp change of 1 Kelvin
what is the difference between the 2 temp scales
is where the 0s occure
how do you convert degrees C to Kelvin
+273
how do you convert Kelvins to degrees C
-273
what does the particle theory say about colliding gas particles
colliding gas particles create pressure
what happens to gas particles when the collide with something
they exert a force on it and the momentum + direction change
what happens to gasses in a sealed container
gas particles smash against container walls = outward pressure
what does the pressure of a gas in a container depend on
how fast the particles are going and how often the collide with walls
what happens if you heat a gas ( leading to something to do with pressure )
particles move faster = more kinetic energy= more harder frequent collisions= more pressure
what is the rule about the temp (in K) and pressure of a gas
temp ( in K ) and pressure are proportional = double the temp u double the pressure
what happens if you put the same amount of gas in a bigger container
pressure decrease ( fewer collision between particles and walls of container )
what happens if the volume of container reduces
pressure increases
what is boyles law equation
p1V1=p2V2
what is boyles law in words
volume is inversely proportional to pressure ( half the pressure double the volume or half the volume double the pressure)
definition of specific heat capacity
energy required to change the temp of an object by 1 degree C per kg of mass
what is the specific heat energy equation
Amount of energy = mass x specific heat capacity x change in temp
what is temperature
Temperature is a measure of the average kinetic energy of the molecules.
what is the equation pressure and temp (in K)in a sealed container
p1 / T1 = p2 / T2
