A water truck's tank has internal dimensions of 14 meters in length and 2 meters in diameter. If the truck's load of pure water is 60 percent of full capacity, how heavy is the load in pounds? Water's density is 62.4 lbft3.

Question

anonymous · Answer

I take it you should assume the tank is cylindrical. The formula for the volume of a cylinder is $$length * \pi * r^2$$ so the volume of this container is

14m * pi * (1m)^2

or

14pi m^3

We want 60% of the volume of the cylinder.

0.60 * 14pi m^3

or

8.4pi m^3

To find the weight we have to use the conversion factor they gave us, but first we have to convert our units into feet because their units are in feet.

8.4pi cubic meters * ( 1 cubic foot /  0.0283168 cubic meters)

Which comes out to about

931.932 cubic feet

Then we convert between volume and weight (cubic feet and pounds) to find the weight  of the water in that 60% of the volume that we just found. (I am going to assume you mean 62.4 lb / ft^3.)

931.932 ft^3 * (62.4 lb / 1 ft^3)

This comes out to

58152.5568 lb