The initial force of the throw overcomes gravity quite easily. Then, gravity begins to bring it back down to earth, making a curved path.
External = R
Internal = r
Volume of hemisperical = 2/3 π(R³-r³)
V= 2/3 π(9.1³ - 8.4³)
V= 336.9 cm³
Basic truss bridge types found in North Carolina (source: HAER) A truss bridge can be characterized by the location of its traffic deck. At a pony truss, the travel surface passes along the bottom chords of trusses standing to either side that are not connected to each other at the top.