Calvin $($mc $=55$ kg$,$ I c $=0\mathrm{.}7$ kg$*$m$2)$ is standing motionless on an icy $($frictionless$)$ part of the driveway. Hobbes hits him with a giant snowball $($mb $=2\mathrm{.}5$ kg$).$ After hitting Calvin, the snowball drops straight down to the ground. But, Calvin starts to slide backwards at $1$ m$/$s$,$ and to rotate at $4$ rpm$.$ To protect himself from further snowballs, Calvin then covers his face with his hands, changing his moment of inertia to $0\mathrm{.}3$ kg$*$m$2.$ How fast was the snowball going before it hit Calvin?