Juan is standing on the street. an ambulance moves toward him and then passes by. what best describes the pitch that juan heats? (a )the pitch remains constant as the ambulance moves toward and then away from juan. (b) the pitch increases and decreases in a repeated pattern as the ambulance passes juan. (c) the pitch drops to a lower pitch once the ambulance passes by juan. (d) the pitch increases to a higher pitch once the ambulance passes by juan.

What’s #16 asking and how do i solve it?

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina.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 2.05cm in front of the eye.)

While carrying a heavy box up the stairs,you set the box on a step and rest. then you pick up the box and carry it to the top of the stairs. describe these actions in terms of balanced and unbalanced forces acting on the box.