Aglass falls to the floor and smashes into hundreds of tiny pieces. is this a physical change? why or why not? this is actually science but me answer this question.

Yes because it changes when the glass hits the floor due to vibration of the glass 

Yes because a physical change involves the physical difference. The glass changing from one piece to hundreds is a physical difference.  In the case of physical reactions, the answer is still yes because a physical reaction involves the item staying the same composition wise. The glass was made of glass when it was in one piece, and the tiny shattered pieces are still glass so it was a physical reaction.