First, two things. 1) Since brass is a solid at standard temperature and pressure, it is unusual to specify its density in fluid volume units, such as gallons. 2) Brass is an alloy comprising differing amounts of different metals, so its density must be specified as a range. Brass is about 8.5 times denser than water. It has a density of 8.4 to 8.75 grams per cubic centimeter. That translates to 70 to 73 pounds per US gallon.
Mass = volume x density
You need the density of the type of brass involved.
The volume of a cube is l3.
7.5 pounds per US gallon
9
Biodiesel has a density 0.88 grams per cubic centimeter. This converts to about 7.34 pounds per gallon.
Nonfat milk is very close in density to water which weighs 8 pounds per gallon.
9.08
About 8.35 pounds per US gallon.
10.3 lbs
Just about 10.68 pounds per gallon.
Roughly 8.5 lbs per gallon. You do the Math.
Approximately 6.8 pounds per gallon.
Tar weighs approximately 7.5 pounds per gallon.
Ammonia weights 5.15 pounds per gallon in contrast to water which weights 8.33 pounds per gallon.
5.67 lbs/gallon @ 60'F
1 Gallon of gasoline weighs 6.152 lbs.
Gas is 6.3 lbs. per gallon. 55 gallons of gas will weigh 346.5 lbs. A steel drum will weigh 40 lbs. and a plastic 55 gallon drum will weigh 20 lbs.
7.5 pounds per US gallon
== Probably close to the weight of water. 8.34 lbs per gallon.