Multiple choice

An aeroplane when flying at a height of 500m. the around passes vertically below another plane at an instant when the Angles of elevation of the two planes from the same point on the ground are 450 and 600 respectivily ,The distance between the two planes at that instant is --

  1. 370m

  2. 366m

  3. 375m

  4. 360m

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let height = 500m. For angle 45°, distance = 500/tan45° = 500m. For angle 60°, distance = 500/tan60° = 500/√3 ≈ 288.7m. Distance between planes = 500 - 288.7 = 211.3m. But this is horizontal distance. Using √3-1: 500(√3-1) = 500(1.732-1) = 366m.