Volume is the level at which something is heard or the amount of space a solid, liquid or gas occupies.
- With sound, its volume is the loudness of the sound.
- With a container, its volume would be its capacity, or how much it can hold.
Volume is often expressed in cubic units determined by the International System of Units.
Measuring the Volume of Sound
The loudness of a sound can be subjective, such as quiet or loud. A more objective measure of sound includes several other factors including:
- Sound pressure level (SPL) - The human ear averages the SPL over a period of 600-1000 milliseconds. After about 1 second, the ear created an average and the level of loudness will seem to become stable.
- Decibels (dB) - This is the ratio between the power and intensity of the sound. The maximum human sensitivities are between 2 and 4 kHz.
Measuring the Volume of Solids
The volume of solids is expressed in cubic measurements, such as cubic centimeter or cubic meter.
Here are examples of ways to measure solids:
- Rectangular prism - Multiply the measurement of the length times the width, then times the height
- Cube - Since all sides are the same measurement, it would be the measurement of any side, or edge, cubed, or a³
- Prism - Find the area of the base, then multiply the area times the height of the prism. Area would be length times width (B), or B x h
- Triangular prism - Find the area of the base (b), then multiply the area times the length (l) between the triangular bases. Area of the base would be ½ times the base times the height (h) of the triangle, or ½bhl
- Cylinder - Find the area of the circular face using pi times the radius squared, then multiply that area times the height of the cylinder, so πr²h
- Pyramid - Find the area of the base and multiply that area times the height of the pyramid and multiply by 1/3, or 1/3Bh
- Square pyramid - Find the area of the base and multiply that area times the height of the pyramid and multiply by 1/3, or 1/3s²h
- Rectangular pyramid - Find the area of the base and multiply that area times the height of the pyramid and multiply by 1/3, or 1/3 lwh
- Sphere - For a sphere, multiply 4/3 times pi, then time the radius cubed, or 4/3 πr³
- Cone - For a cone, it is the area of the circular face, or πr², then multiply by 1/3 and the height of the cone, or 1/3 πr²h
Measuring the Volume of Liquids
Liquids are fairly simple to measure, remembering that 1000 cubic centimetres equals 1 litre and 1000 litres equals 1 cubic metre.
Here are examples of ways to measure liquids:
- Barrels - Barrels can be dry barrels or fluid barrels, such as oil and water barrels. The specific amount of volume a barrel holds has differed over time and depending on the type.
In Europe, the term “barrel” as a unit of measure has ranged from signifying around 100 litres to signifying around 1,000 litres.
In the US, a beer barrel is around 31 gallons while an oil barrel is around 42 gallons.
- Gallons - A gallon is equal to 128 ounces; four quarts; eight pints and around 3.781 liters.
- Measuring cups - Measuring cups come in various sizes and can be used to measure liquid or dry goods. A set of measuring cups for dry goods usually includes a ¼ of a cup, a ⅓ of a cup, a ½ cup and a 1-cup measure.
- Measuring spoons - Measuring spoons also come in various sizes and can measure dry or liquid goods. A standard set of measuring spoons generally contains a ¼ teaspoon measure; a ½ teaspoon measure; a 1 teaspoon measure; and a 1 tablespoon measure.
- Pints - A pint is equal to 1 milliliter, .125 gallons, and .5 quarts.
- Quarts- A quart is equal to 946.353 milliliters, .25 gallons and four quarts.
Measuring the Volume of Gases
Here are examples of ways to measure volume of gases:
- Displace fluid - This method can be used to calculate the volume of gas. The volume of fluid displaced would equal the volume of the gas.
- Use a gas syringe - This is a laboratory instrument that can be used to withdraw a certain volume of gas from a closed system or to measure the volume of gas from a chemical reaction.
- Use a spirometer - It measures the volume of air coming into and being expelled out of your lungs, called tidal volume.
- Trap the gas - Use a balloon to trap the gas coming from a reaction. Then calculate the volume of the sphere.
- For the volume of compressed gas in a cylinder, apply this equation, the Ideal Gas Law: PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant and T is the absolute temperature
Now you have learned plenty of different ways to measure volume.