Question 332278
How far away, in km, is an airplane measured by a radar wave that that takes 9.36 x 10^-4 s to go and return to the radar unit that is measuring the distance? Express your answer to the nearest km. 
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You didn't give the speed of the radar beam, so I'll assume 300,000 km/sec
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If the roundtrip takes 9.36E-4 seconds, it takes 1/2 that to get to the airplane, = 4.68E-4 seconds
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3E5 km/sec * 4.68E-4 sec = 14.04E1 km
=~ 140 km