1-5. A waiter is holding a cup on a tray. As the waiter walk forward, the bottom of the cup gets a little wet, so the cup becomes slippery. The waiter suddenly slows down with the tray and the cup slides on the tray. Assume the tray stays horizontal the whole time. In which direction does the little bit of friction from the tray acts on the cup during the slide? a. Forwards Backwards . Up d. Down Bonus: Since the glass is now so slippery, how should the waiter hold the tray when he speeds up again to avoid the glass from slipping? How about when he has to make turns