A wave travels with a speed of 78m/s in air and it has a frequency of 42hz. What is the wavelength of this wave?

The mass of a muon is 207 times the electron mass; the average lifetime of muons at rest is 2.21 μs. in a certain experiment, muons moving through a laboratory are measured to have an average lifetime of 7.04 μs. for the moving muons, what are (a) β (b) k, and (c) p? the rest energy of the electron is 0.511 mev.

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.

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.)