Chapter 3 (B- 3.5 to 3.8) Pressure Flashcards
What is pressure
force acting per unit area
Pressure formula
Force/area
Pressure unit
Pascal (Pa)
1 Pascal is equal to
1 Newton/Metre^2
n/m^2
Relationship between pressure and area
Inversely related
Pressure increases as area decreases
Factors that affect the pressure acting at any point on a liquid
i) depth of the point bellow the surface of the liquid
ii) density of the liquid (More dense, more pressure)
iii) Acceleration of free fall at the point
Equation for LIQUID pressure
P = hpg h = depth p = density (Rho) g = acceleration of free fall
What is atmospheric pressure
Pressure exerted by the atmosphere
What is a barometer
an instrument used to measure atmospheric pressure
Relationship between atmospheric pressure and height from the surface of the earth
inverse
Density of the atmosphere decreases as the height from the surface increases
What does an object experience as a result of pressure
forces at right angles to all of its surfaces
What are the 3 gas laws
Boyle’s law
Charle’s law
Gay lussac’s law
What is Boyle’s law
States that for a fixed mass of gas at a constant temperature, pressure is inversely proportionate to volume.
Equations for Boyle’s law (2 eqns)
P * V = constant
p1v1 = p2v2
How to explain Boyle’s law in terms of kinetic theory
In a gas, molecules are constantly bouncing off each other and the walls of the container. The force of these collisions causes pressure. If the volume is halved and temp is maintained constant, then there are twice as many gas molecules in each cubic meter. Every second, there are twice as many collisions, resulting in more force and pressure.
