Ali was sitting at her desk in the front of the room. On the board was the day’s lesson. Once students would come in she will go more in-depth—if they have questions that is.
Consider that the physical laws that govern the muggle world--cause and effect, action and reaction, conservation of energy, that sort of thing--are secondary in the wizard way of seeing things. For us the key is intention and power. Does a wizard have to see something to Summon it, or even know exactly what that thing is? Nope. If they have the intention and power to make that Summoning Charm do exactly what she wants. When learning it, one needs to specify, even see the object in question.
Once we free our minds of the shackles of Muggle physics, magic becomes that in a way more understandable, and it soon becomes obvious that magic is really the manipulation of magical power by the intention and focus (by means of a wand and words, usually) of the caster. The exact physics of the spell--how it works, how it's cast, what it does--can be different every time, because physical laws aren't involved, emotions and intentions are.
HW: Write a short paragraph about how muggles vary in their perspective of the world than wizards. (Why can wizards have less natural limitations in terms of their magic?)