Blocks A $($mass $4\mathrm{.}50$ kg$)$ and B $($mass $6\mathrm{.}50$ kg$)$ move on a frictionless, horizontal surface. Initially, block B is at rest and block A is moving toward it at $4\mathrm{.}00$ m$/$s$.$ The blocks are equipped with ideal spring bumpers. The collision is head$-$on$,$ so all motion before and after the collision is along a straight line. Let $+$x be the direction of the initial motion of block A$.$

Find the maximum energy stored in the spring bumpers. Find the velocity of block A when the energy stored in the spring bumpers is maximum. Find the velocity of block B when the energy stored in the spring bumpers is maximum. Find the velocity of block A after they have moved apart. Find the velocity of B after they have moved apart.