Regan has an empty glass cup. it has a mass of 0.3 kg. she drops the cup on the ground and it shatters into several pieces. if she collected all of the pieces of the cup, how much mass would all of the pieces have combined?

The Answer Is "exactly .3 kg

This is because during a physical change, like being broken into parts, mass is conserved. The glass cup had a mass of 0.3 kg before it was broken, so if Regan collected all of the broken pieces, they would have a combined mass of exactly 0.3 kg.

well the answer is 2!