Blocks A (mass 4.00 kg ) and B (mass 6.00 kg ) move on a
frictionless, horizontal surface. Initially, block B is at rest and
block A is moving toward it at 5.00 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...