When Pulsars were first discovered, they were a mystery. Some even thought they might be signals from aliens! In a paragraph, explain the basics of our current understanding of what a pulsar is and how such an object forms.

The sun generates both mechanical and electromagnetic waves. which statement about those wave is true?

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

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