Imagine good ol' Jon Pankey here sitting in a frictionless wheeled chair, with
the inevitable wad of chewing tobacco lodged in his mouth... Assuming he weighs
50 kg (including the chair), and is skilled enough in the art of spitting to launch one cubic
centimeter of "projectile" at 5 m/s each time he spits, how many "projectiles"
would need to be launched to get him moving at 1 m/s? Also assume he periodically
drinks some water to replace the mass he is launching...