What happens to the object when positive velocity and positive acceleration occur?

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?

Why don't you see your reflection in water with waves or repples

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90