Q:

An aero plane flying horizontally at a height of 3 km. Above the ground is observed at a certain point on earth to subtend an angle of 60⁰. After 15 sec flight, its angle of elevation is changed to 30⁰. The speed of the aero plane (taking √3=1.732)

• 1
  230.63 m/sec
• 2
  230.93 m/sec
• 3
  235.85 m/sec
• 4
  236.25 m/sec