The product of flow and concentration gives mass per unit time.

The term "density" is not used in its traditional sense of mass per unit volume.

Lower strings are thicker, thus having a greater mass per unit length.

The density of an object is defined as mass per unit volume.

The density is the mass per unit volume of a fluid (or any material for that matter.

Mass per unit length: All other factors the same, the thinner the wire, the higher the pitch.

There were two solutions: increase the tension in the wire or reduce its mass per unit length.

Hence the mass per unit volume of the gas (its density) decreases.

Mica is a commonly-used material due to its low mass per unit area.

Molar mass is the mass per unit amount of substance.

Inversely proportional to the square root of the mass per unit length.

The "side centroid" comes from considering the sides to have constant mass per unit length.

Detonating cord is rated in explosive mass per unit length.

Essentially, hot air is lighter than cool air, because it has less mass per unit of volume.

From this the mass per unit length of the string / wire can be derived.

Mass density- A materials mass per unit volume, also just called density.

Using linear, direct sensing of mass per unit volume, measurement system within a reinforced rubber tube.

Specific mass, actually meaning volume-specific mass, or mass per unit volume.

Addressing your question directly: Density has an unambiguous definition: The mass per unit volume.

Given two strings of equal length and tension, the string with higher mass per unit length will produce the lower pitch.

Both gross and net primary production are in units of mass per unit area per unit time interval.

Technically, this is not a flux, since flux has dimensions of mass per unit area per unit time.

The pitch of a string can also be varied by changing the linear density (mass per unit length) of the string.

String instruments are tuned by varying the strings' tension because adjusting length or mass per unit length is impractical.

These may be combined to understand the concept of pressure, which is force per unit area and density, which is mass per unit volume.