Density is best described as the heaviness of a liquid. By definition, it is the amount of mass per unit volume. The actual equation is the ρ = mass/volume. Density is represented by the Greek letter "ρ." The SI units for density are kg/m3.
Pressure is defined as a force per unit area. So using the equation, the greater the surface area of a given object, the lesser the pressure. When area is constant but the force is increased, then force is proportional to pressure. Area is inversely proportional to pressure. The equation for pressure is P= Force/Area with "P" standing for pressure. The unit for pressure is 1 Newton/m2, also known as a Pascal.
Density can also be used to determine pressure. Another pressure equation is P= ρgh, with "ρ" representing density, "g" as the acceleration constant (usually 10 m/s^2), and "h" as the height of the fluid's container. In this equation, pressure is directly proportional to density and inversely proportional to height.
Pressure of an ideal gas is figured by multiplying the molar amount ("n") of a gas by the gas constant "R," known as 8.316 J/mol-K, and the temperature in degrees Kelvin. This number is then divided by the volume, "V." Therefore, the volume of a gas is inversely proportional to the pressure. The equation is written as P=nRT/V.