P = F/A
unit of measure is pascal.
The pressure P is the ratio of the force F acting perpendicularly to a surface area A.
Pressure applied to an eclosed fluid is transmitted undimnished to every part of the fluid and to the walls of the container. Pressure is a force acting on a liquid which must act on a container area.
Liquids are relatively incompressible.
Pascal's principle is applicable both to liquids and gases. The pressure on a gas is not transmitted as quickly as in a liquid.
Buoyancy + Archimede's principal
-Buoyancy: an upward force acting on an object in a liquid that balances part of the object's weight.
-Buoyancy force: the upward acting force.
-Archimede's principal: an object in a fluid is buoyed upward with a force equal to the weight of the volume of the fluid displaced by the object. This principal applies to gases as well as liquids. An object will float in a fluid if the density of the object is less than or equal to the density of the fluid.
-Standard atmospheric pressure at sea level supports a column of mercury 76cm or 760mm in height. Barometic pressure is reported in inches, centimitres or millimitres of mercury. (one torr = 1mm of Hg)
-Atmospheric pressure is measured by means of a barometer.
-Speed: rate of movement (scalar)
-Velocity: the speed of something in a particular direction (vector)
Motion involves a change of position in time.
Is the velocity at any given instant in time.