Oh, okay... Arresto Momentum had some similar properties to Impedimenta, so Mo was gonna count that as a win. Not a right answer, but an 'almost right' answer. He wondered if Cat would give him cupcakes for getting an answer almost right.

"Professor, I bet you could use the spell to slow yourself down if you were jumping or falling from a great height. Like from Ravenclaw tower or something." Mo may have glanced at the Gryffindor Quidditch captain at that suggestion. New experiment?