Relative Velocity in Two Dimensions
Airplanes A and B are flying with constant velocity in the same vertical plane at angles and with respect to the horizontal as shown in the figure. The speed of A is m/s. At time s, an observer in A finds B at a distance of m. This observer sees B moving with a constant velocity perpendicular to the line of motion of A. If at , A just escapes being hit by B, in second is

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Answer: (d)
- B is seen moving perpendicular to A's path, so the component of along A's direction equals .
- Angle between the two paths is : m/s.
- Relative speed (perpendicular to A's path) m/s.
- s
- So the answer is (d) .