(a) A possible means for making an airplane invisible to radar is to coat the plane with an antireflective polymer. If radar waves have a wavelength of 2.84 cm and the index of refraction of the polymer is n = 1.36, how thick (in cm) would you make the coating? (Assume that the index of refraction of the plane is higher than that of the coating. Also assume that the radar waves are normal to the surface of the coating. Give the minimum thickness that would make the airplane invisible to radar.) 0.52 v cm (b) What If? Newer radar systems now use the VHF and UHF bands in order to detect stealthy aircraft. If a radar system operates with a frequency of 423 MHz (in the UHF band), what minimum thickness of coating (in cm) is needed to render an aircraft invisible to this radar band? 0.13 X cm (c) Will an antireflective polymer coating make the airplane invisible to both the 2.84 cm X-band radiation in part (a) and the 423 MHz UHF-band radiation in part (b)? O Yes, an antireflective polymer coating will make the airplane invisible to both radar systems. O No, an antireflective polymer coating will not make the airplane invisible to both radar systems.

Astronomers observe the chromosphere of the Sun with a filter that passes the red hydrogen spectral line of wavelength 656.3 nm, called the H, line. The filter consists of a transparent dielectric of thickness d held between two partially aluminized glass plates. The filter is held at a constant temperature. (a) Find the minimum value of d that produces maximum transmission of perpendicular H, light if the dielectric has an index of refraction of 1.494. (Assume that the glass's refractive index exceeds 1.494.) nm (b) If the temperature of the filter increases above the normal value, increases its thickness, what happens to the transmitted wavelength? (Its index of refraction does not change significantly.) O It increases. O It decreases. O It remains unchanged. (c) The dielectric will also pass what near-visible wavelength? One of the glass plates is colored red to absorb this light. nm Additional Materials O eBook

(a) A possible means for making an airplane invisible to radar is to coat the plane with an antireflective polymer. If radar waves have a wavelength of 2.72 cm and the index of refraction of the polymer is n = 1.80, how thick (in cm) would you make the coating? (Assume that the index of refraction of the plane is higher than that of the coating. Also assume that the radar waves are normal to the surface of the coating. Give the minimum thickness that would make the airplane invisible to radar.) cm (b) What If? Newer radar systems now use the VHF and UHF bands in order to detect stealthy aircraft. If a radar system operates with a frequency of 441 MHz (in the UHF band), what minimum thickness of coating (in cm) is needed to render an aircraft invisible to this radar band? cm (c) Will an antireflective polymer coating make the airplane invisible to both the 2.72 cm X-band radiation in part (a) and the 441 MHz UHF-band radiation in part (b)? Yes, an antireflective polymer coating will…

What is the index of refraction of a material in which the red-light wavelength is 495 nm? Wavelength of red-light in vacuum is  692 nm.

How thick is a layer of oil floating on a 52cm bucket of water. You measure your laser beam to take 2.33 ns going straight through the layers