(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.

(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.

University Physics Volume 3

17th Edition

ISBN:9781938168185

Author:William Moebs, Jeff Sanny

Publisher:William Moebs, Jeff Sanny

Chapter3: Interference

Section: Chapter Questions

Problem 47P: To save money on making military aircraft invisible to radar, an inventor decides to coat them with...

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