P1.3 - Pressure Flashcards
why do balloons expand when air is blown into it?
- gases move quickly in all directions
- so, they collide with the surface of the ballon
- each collision produces a force
- so, when more air is blown, more force is applied to the balloon causing it to expand
how does temp affect gas pressure?
- causes the particles to move around faster
- causes more frequent collisions
- makes more force on surface
- more pressure
what is the unit of pressure?
Pa (Pascals)
what is the unit of force?
N (newtons)
what is the unit of area/surface area?
m^2 (meters squared)
what is the equation to work out pressure
force / area
force over area
what is extrapolating?
- basically ‘estimating’ what the result would be on a graph
(shown as a dotted line) - an extended dotted line downwards
what can you use to measure the pressure of a gas?
a manometer
what can you use to measure the pressure of air that is trapped in a bottle?
a pressure gauge
explain why it is dangerous to throw a canister full of pressurised gas in a fire?
- the gas particles heat up
- increasing the pressure within the can
- start moving quickly in all directions, exert a high force on the surface area of the canister
- if canister is unable to width stand the force, it would explode
explain the extent to which pressure is, or is not proportional to the temperature of a gas
- temp and pressure have a directly proportional relationship as long as the volume is constant
- the pressure of gas also depends on its volume as well as its temperature
How does a gas react to:
(a) a higher pressure?
(b) a lower pressure?
(a) - it compresses
(b) - it expands
State the direction of the force of a gas on the surface of a container
90 degrees (right angle)
If pressure is increased (within a closed system) how does the volume change?
- and explain the relationship (name)
The volume decreases
INVERSELY PROPORTIONAL
What is the equation for pressure and volume?
+ explain why
Pressure(Pa) x volume (m^3) = constant
+ since pressure and volume are inversely proportional, if you half one the other doubles, and so their product would always equal to the same amount