a tennis ball is hit with a racket. its speed when leaving the racket is 13.5 m/s, if the ball is in the
air for 3.2 seconds, how far did it travel right before hitting the ground (ignore air resistance)?

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

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.)

Imagine an isolated positive point charge q (many times larger than the charge on a single proton). there is a charged particle a (whose charge is much smaller than charge q) at a distance from the point charge q. on which of the following quantities does the magnitude of the electric field created by charge q at particle a's position depend? check all that apply.the type of the charge on the charged particle athe relative orientation between q and a (while the distance between q and a is fixed)the specific location of the charged particle a (while the distance between q and a is fixed)the amount of the charge on the point charge qthe specific location of the point charge q (while the distance between q and a is fixed)the distance between the point charge q and the charged particle athe amount of the charge on the charged particle a