Box 1 has less speed than box 2 because in the diagram you can see box 1 and 2 collide each other and after the crash you can see box 1 moving in opposite direction in a faster speed than before the crash. You can also see that Box 2 decreased its speed. This shows that box 1 has a lesser mass than box 2 because box one change its direction by bouncing off a heavier box.

Box 1 has more mass than Box 2. I know this because when the two boxes crashed, they experienced the same strength force in opposite directions. Since Box 1 had less change in speed from this force, it must have more mass than Box 2. That's because when the same strength force is exerted on objects of different mass, the less massive object will have a greater change in velocity.

Box 1 and Box two are the same mass because...