Pressure

is the amount of force per unit area applied to an object's surface

Atmospheric pressure

the ratio of the weight of all the air above you to surface area

Fluid

is a liquid or a gas, anything that flows

Buoyant force

is an upward force applied by a fluid on an object in the fluid

Archimedes' principle

the weight of the fluid that an object displaces is equal to the buoyant force acting on the object

Bernoulli's principle

states that the pressure of a fluid decreases when the speed of the fluid increases

Drag fore

is a force that opposes the motion of an object through fluid

Elevation

the distance above sea level

Density

a measure of how compact the mass in a substance or object is