Que:3. 5 Points to your house at Hogwarts if you could answer any of these questions

We have seen the shock occasionally lift the body/throw it backwards. Because Dumbledore was already at the edge of the tower, it was enough to throw him over that edge, so he fell.

Spells probably vary from wizard to wizard so a spell might have a different effect like being thrown in the air or not.

He is Dumbledor. Like how Harry survived you know who