Consider calculating the total weight of an amount of sand since it may be too difficult to place it all on a scale. The weight of an amount of sand depends on its volume and weight density (See Reference 1). Volume measures the amount of space the sand occupies while weight density determines its compactness. Sand is composed of fine granular particles that soak up water easily, so its wet-weight density differs from its dry. Specifically, the dry density of sand is 100 lbs per cubic foot while wet sand has a weight density of 120–130 lbs per cubic foot (See Reference 2).

Fill the one-gallon bucket with sand. Dump the sand out in a new pile. Continue this process until all the sand has been used. Record the number of bucket-fulls of sand. This is the volume of all the sand in gallons. For example, if 10.5 bucket-fulls were required, the volume of sand is 10.5 gallons.

Convert the volume to units of cubic feet by dividing by 7.481, because 7.481 gallons equals a single cubic foot (See Reference 3). Performing this step leads to 10.5 gallons divided by 7.481 gallons per cubic foot, or a volume of 1.4 cubic feet.

## Sciencing Video Vault

Multiply the volume by weight density to obtain the weight of the sand in pounds (See Reference 1). Assume the sand is dry for the example. Completing the exercise leads to 1.4 cubic feet times 100 lb per cubic foot, or a weight of 140 lbs.

#### Tip

Convert from kg per cubic meter to lb per cubic foot by dividing by 16.02 (See Reference 1). The weight density of wet, packed sand equals 130 lb per cubic foot (See Reference 2).