An astronaut in orbit can just resolve two point sources on the earth that are 75.0 m apart. assume that the resolution is diffraction limited, and use rayleigh's criterion. what is the astronaut's altitude above the earth? treat her eye as a circular aperture with a diameter of 4.00 mm (the diameter of her pupil) and take the wavelength to be 500 nm.

Based on the concept of the wave-like nature of light, huygens' theory of light postulates that the more light was "bent" by a substance the slower it would move while traversing across that substance. a) deflection b) interference c) refraction d) resonance

To understand the behavior of the electric field at the surface of a conductor, and its relationship to surface charge on the conductor. a conductor is placed in an external electrostatic field. the external field is uniform before the conductor is placed within it. the conductor is completely isolated from any source of current or charge. part a: which of the following describes the electric field inside this conductor? it is in the same direction as the original external field.it is in the opposite direction from that of the original external field.it has a direction determined entirely by the charge on its surface.it is always zero. part b: the charge density inside the conductor is: 0non-zero; but uniformnon-zero; non-uniforminfinite part c: assume that at some point just outside the surface of the conductor, the electric field has magnitude e and is directed toward the surface of the conductor. what is the charge density η on the surface of the conductor at that point? express your answer in terms of e and ϵ0

Your physics assignment is to figure out a way to use electricity to launch a small 6.0-cm-long plastic drink stirrer. you decide that you'll charge the little plastic rod by rubbing it with fur, then hold it near a long, charged wire, as shown in figure p23.56 . when you let go, the electric force of the wire on the plastic rod will shoot it away. suppose you can uniformly charge the plastic stirrer to 10 nc and that the linear charge density of the long wire is 1.0 x10-7 c/m. what is the net electric force on the plastic stirrer if the end closest to the wire is 2.0 cm away?