Pressure, Gravity, and Moments

Density

Mass per unit volume

SI Unit: kg m^-3

Density=\frac{mass}{volume}

\rho=\frac{m}{V}

Pressure

Force per unit area

Pressure=\frac{Force}{Area}

P=\frac{F}{A}

Pressure due to a liquid

P=\rho gh

h = depth, g = gravity

Archimedes Principle

Upthrust of an object is equal to the weight of the fluid displaced.

Law of Floatation

Weight of a floating body is equal to the weight of the fluid it displaces.

Hydrometers - measure density

e.g. home brewing (alcohol percentage)

Boyle’s Law

At con