# ch14 COPY Flashcards

how do you get impulse from a force time graph

the area under a force-time graph is equal to the impulse

motion of gas particles how do gas particles exert pressure

gas particles are in constant random brownian motion,

They continuously collide with each other and the walls of their container, causing a change in momentum (impulse) producing a force

this force results in pressure (p = F / A), which exerts a pressure on the containers

describe the pathing of gas particles

particles take a random path, they don’t travel in a straight line because they’re constantly changing direction due to collisions

displacement is proportional to the square root of number of steps

what is boyle’s law

provided that temp and amount of gas remains constant, pressure is inversely proportional to the volume

pV = constant

practical to look at boyle’s law

set up as shown, must have a trapped volume of gas whose pressure can be changed and whose volume measured

increasing pressure forces oil into the calibrated tube, while decreasing allows oil out the tube

by keeping temp constant, you can investigate the variation in volume with pressure

uncertainties: tube might fracture

relationship between pressure and number of molecules

provided that the volume is kept constant

the number of molecules is directly proportional to the pressure

how to work out number of molecules N

number of molecules N = moles n * avagadro constant Na

what is an ideal gas

a model for a gas where the particles are assumed to have negligible volume, there are negligible forces between particles except during collisiosn and the collisions are perfectly elastic,

what is charle’s law

at constant pressure, volume is directly proportional to absolue temperature T

what is the pressure law:

at constant volume, pressure is directly proportional to absolute temperature T

how to go from degrees to kelvin

kelvin = degrees celsius + 273

how to determine absolute 0

set up apparatus as shown

measure length L of the air column at different temperatures to see how the volume of enclosed gas is changing

you can mount the tube in a tall glass beaker of water whose temp can be changed

you must however be careful to ensure temp in water is similar to the temp in the enclosed air of the capillary tube

the data obtained can be used to find absolute temperature

ideal gas equations

pV = nRT

pV = NkT

p = pressure

v = volume

n = number of moles

N = number of molecules

R = gas constant

k = boltzmann constant

T = temperature (kelvin)

ideal gas law (molecules in a box)

what is the c² representing

pV = 1/3Nmc²

c² is for the mean squared

how to get value of molecular speeds

the value of molecular speeds is the square root of the mean square speed

this is the root mean square speed

RMS