I need to find the volume of a vertical gas tank that is not filled all the way. we will be given the height of a cylindrical water tank with a hemispherical (half sphere) cap on each end (both caps with the same radius) and a specified height of the water in the tank determine the volume of the water.
this looks like a pill capsule. i could break it down into three parts but was wondering if there was one formula i could use. any help would be great.

oh... here is what i have so far, i broke it into 3 parts. 2 were semi spheres and the middle was a cylinder, but did not know how to find the volume if the water height was in the bottom sphere and not filled all the way.
thanks again.