Charge of uniform density (20 nC/m?) is distributed over a cylindrical surface
(radius -1.0 cm), and a second coaxial surface (radius = 3.0 cm) carries a uniform charge
density of -12 nC/m2. Determine the magnitude of the electric field at a point 4.0 cm from
the symmetry axis of the two surfaces.
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One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

What is the name for the remnant of an asymptotic giant that has lost its shells? black dwarf white dwarf yellow giant black hole

Most short-period comets do not have randomly oriented orbits because