Baseball bat A baseball bat has mass M and moment of inertia Mk2 about any axis through its centre of mass G that is perpendicular to the axis of symmetry. The bat is at rest when a ball of mass m, moving with speed u, is normally incident along a straight line through the axis of symmetry at a distance b from G.
Show that, whether the impact is elastic or not, there is a point on the axis of symmetry of the bat that is instantaneously at rest after the impact and that the distance c of this point from G is given by bc = k2. In the elastic case, find the speed of the ball after the impact.
[Gravity (and the batter!) should be ignored throughout this question.]