An FM radio transmitter, operating at a frequency of 120 MHz, Is at top a 100 m tower. An airplane is in flight over the ocean at an altitude of 2000 m. Radio waves reach the airplane directly from transmitter and by reflection from the surface of the ocean. When the airplane is 86 km from the tower, the pilot observes that radio reception has faded due to destructive interference of the waves in the two paths. Assume the wave reflected from reflected path arrive at the airplane delayed, with respect to the direct path. The time interval of this delay, in ns is closest to : A) 16 (B) 20 (C) 14

An FM radio transmitter, operating at a frequency of 120 MHz, Is at top a 100 m tower. An airplane is in flight over the ocean at an altitude of 2000 m. Radio waves reach the airplane directly from transmitter and by reflection from the surface of the ocean. When the airplane is 86 km from the tower, the pilot observes that radio reception has faded due to destructive interference of the waves in the two paths. Assume the wave reflected from reflected path arrive at the airplane delayed, with respect to the direct path. The time interval of this delay, in ns is closest to : A) 16 (B) 20 (C) 14