I think there's a typo because the answer I'm getting is very large.
This is what I'm getting
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c = speed of light
c = 3.0 x 10^8 m/sec approximately
This is roughly 300 million meters per second
The time it takes the signal to reach the aircraft and come back is 1.4 x 10^3 seconds. Half of this time period is going one direction (say from the radar station to the aircraft), so (1.4 x 10^3)/2 = 7.0 x 10^2 seconds is spent going in this one direction.
distance = rate*time
d = r*t
d = (3.0 x 10^8) * (7.0 x 10^2)
d = (3.0*7.0) x (10^8*10^2)
d = 21.0 x 10^(8+2)
d = 21.0 x 10^10
d = (2.1 x 10^1) * 10^10
d = 2.1 x (10^1*10^10)
d = 2.1 x 10^11 meters
d = 210,000,000,000 meters (this is 210 billion meters; equivalent to roughly 130,487,950 miles)
