Question:
Ten small planners are flying at a speed of 150 km/h in total darkness in an air space that is 20 × 20 × 1.5 km3 in volume. You are in one of the planes, flying at
random within this space with no way of knowing where the other planes are. On the average about how long a time will elapse between near collision with your
plane. Assume for this rough computation that a safety region around the plane can be approximated by a sphere of radius 10 m.
Solution:
Time = distance/speed
No.of particles per unit volume v = N/volume
n = 0.0167 km-3
d = 10 × 10-3 km
v = 150 km/hr
Therefore, time = 225 hrs