Gases and Atmospheric Pressure
Gases and Atmospheric Pressure
Three types of motion and kinetic energy
-particles in a substance have three type of motion and therefore three types of kinetic energy
-vibrational motion -vibreational kinetic energy -all particles have this type of energy
-rotational motion -rotational kinetic energy -particles in liquid and fases have some solids have this energy type
-translational motion -translational kinetic energy -only particles in liquid and gas have this type of energy
Gases and Pressures Changes
Pressure
-recall: pressure id the force that is exerted on an object perunit of surface area
-formula: pressure = force/area OR P = F/A
-the SI unit for force is newtons (N) and unit for area is square meters (m2)
-therefore pressure has a unit of N/m2
-other units of pressure -Pascal (Pa) -millitetres mercury (mmHg) -atmosphere
Atmospheric Pressure
-the gas molecules in our atmoshpere are pulled down towards earth's surface by gravity
-these molecules exert pressure on all objects on earth
-earth's atmospheric pressure is therefore the force* that a column of air that exerts on earth's surface, divided by the area of earth's surface at the base of the column
-therefore the force that the column of air exerts is its *weight
-force is exerted equally in all directions
Atmospheric Pressure (atm)
-atmospheric pressure is how much pressure is being applied to something at sea level
-column of air extending from sea level to the top of the atmosphere
-cross-sectional area of 1m2
-mass of thie column of 10329 kg
-therefore, it weighs (force) 101325 N (because 10239 kg x 9.81 m/s2)
-pressure = force/area =101235 N/1 m2 =101235 N/m2
-therefore 101325 N/m2 will be equal to 1 atm
-this is the same concept as moles where 6.02 x 1023 particles = 1 mol
Atmospheric Pressure and Altitude
-at high altituds, the atmospheric pressure is lower -this is because the column pf air is smaller and therefore weight less
Three types of motion and kinetic energy
-particles in a substance have three type of motion and therefore three types of kinetic energy
-vibrational motion -vibreational kinetic energy -all particles have this type of energy
-rotational motion -rotational kinetic energy -particles in liquid and fases have some solids have this energy type
-translational motion -translational kinetic energy -only particles in liquid and gas have this type of energy
Gases and Pressures Changes
Pressure
-recall: pressure id the force that is exerted on an object perunit of surface area
-formula: pressure = force/area OR P = F/A
-the SI unit for force is newtons (N) and unit for area is square meters (m2)
-therefore pressure has a unit of N/m2
-other units of pressure -Pascal (Pa) -millitetres mercury (mmHg) -atmosphere
Atmospheric Pressure
-the gas molecules in our atmoshpere are pulled down towards earth's surface by gravity
-these molecules exert pressure on all objects on earth
-earth's atmospheric pressure is therefore the force* that a column of air that exerts on earth's surface, divided by the area of earth's surface at the base of the column
-therefore the force that the column of air exerts is its *weight
-force is exerted equally in all directions
Atmospheric Pressure (atm)
-atmospheric pressure is how much pressure is being applied to something at sea level
-column of air extending from sea level to the top of the atmosphere
-cross-sectional area of 1m2
-mass of thie column of 10329 kg
-therefore, it weighs (force) 101325 N (because 10239 kg x 9.81 m/s2)
-pressure = force/area =101235 N/1 m2 =101235 N/m2
-therefore 101325 N/m2 will be equal to 1 atm
-this is the same concept as moles where 6.02 x 1023 particles = 1 mol
Atmospheric Pressure and Altitude
-at high altituds, the atmospheric pressure is lower -this is because the column pf air is smaller and therefore weight less