So I was forced by my principal to prepare a presentation for the morning assembly a few days from now (as a punishment :| ). Worst part is: The presentation has to be about a........Yo-yo -.- Specifically the physics behind bouncing a yo-yo up and down. I don't think i'm good at public speaking (especially in front of 200+ students). Any tips on public speaking or on the matter itself would be helpful. P.S: I read a few articles online talking about being confident, preparing...etc. Anything extra would be helpful.