A nozzle which is attached to the end of a 4-in fire hose has a length of 1 ft and a diameter at the discharge end of 1 in. If it has a uniform thickness of 5/16 in and is made of brass, find the weight of material used in the manufacture of 1000 such nozzles. (Brass weighs 520 lb per cu. ft)

please help me how to solve this. i really don't know how. thanks in advance!

2 answers

you know that weight is volume * density. You know the density, so what is the volume of brass?

\It appears we are dealing with the frustrum of a cone, narrowing from 4" to 1", with a thickness of 5/16 in. Theus, the outside diameter goes from 4.3125" to 1.3125"

Now just figure the volume of the larger shape less the volume of the inner cone, and that is the volume of brass.

Then you can get its weight, and multiply that by 1000.

The only hard part is figuring the volume of a frustrum of a cone. Google is your friend.
4709.05 lb.