# Unit 1: Fluids

## Concepts

**Density** - Mass per unit volume of a fluid, can also be stated as how "compact" something is.

**Buoyancy** - A force that's created when an object is submerged in a lfuid and is exerted upward on the object by the fluid.

**Apparent mass** - The mass an object appears to have when submerged in a fluid.

**Atmospheric pressure = ** At sea level, this is 1.013 x 10^{5} N/m^{2}.

**Archimedes' Principle** - The buoyant force on an object immersed in a fluid is equal to the weight of the fluid displaced by the object.

**Bernoulli's Principle** - Where the velocity of a fluid is high, the pressure is low, and where the velocity is low, the pressure is high.

**Pascal's Principle** - If an external pressure is applied to a confined fluid, the pressure at any point in the fluid increases by the same amount.

## Formulas

**ρ = m/V** - Used to find density. Density = mass/volume.

**mg = ρVg** - Another formula to find density. (Mass)(force of gravity) = (density)(volume)(force of gravity).

**P = ρgh** - Used to find pressure at a point. Pressure = (density of fluid)(force of gravity)(height of fluid above the point).

**P = P _{o} + ρgh** - Used to find absolute pressure at a point. Absolute pressure = Atmospheric pressure + (density of fluid)(force of gravity)(height of fluid above the point).

**A _{1}V_{1} = A_{2}V_{2}** - The continuity equation, used to show that the volume of whatever goes through one cross sectional area must equal the volume that comes out of the second cross sectional area.

**P _{1} + ρgy_{1} + (1/2)ρv_{1}^{2} = P_{2} + ρgy_{2} + (1/2)ρv_{2}^{2}** - Bernoulli's principle as an equation.