Show that in a collision between a heavy particle and an electron the highest speed the electron can receive is 2mv/(m+mo), where v is the speed of the heavy particle and m and mo are the rest masses of the heavy particle and the electron. assume non-relativistic particles.

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

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?

How do you know how many valence electrons an atom has?