On a highly polished, essentially frictionless lunch counter, a 0.500 kg submarine sandwich moving 3.00 m/s to the left collides with an 0.250 kg grilled cheese sandwich moving 1.20 m/s to the right.
(a) If the two sandwiches stick together, what is their final velocity?
(b) How much mechanical energy dissipates in the collision? Where did this energy go?