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The speed of sound in water is 1,500. m/s. Suppose a sound wave is transmitted through water from one submarine, is reflected off another submarine 15 km away, and returns to the sonar receiver on the first submarine. What is the round-trip transit time for the sound wave?
s = v t 1 km = 1000 m
t = s / v 15 km * ( 1000 m / 1 km) = 15000 m
t = 15000 m / 1500 m/s
t = 10 s

supposedly this answer is wrong

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The speed of sound in water is 1,500. m/s. Suppose a sound wave is transmitted through water from one submarine, is reflected off another submarine 15 km away, and returns to the sonar receiver on the first submarine. What is the round-trip transit time for the sound wave?
        s = v t                     1 km = 1000 m 
        t = s / v                 15 km * ( 1000 m / 1 km) = 15000 m
        t = 15000 m / 1500 m/s 
        t = 10 s

supposedly this answer is wrong

anonymous · Answer

It asks for round trip time, so I think you're supposed to double the time to 20 s.

taramgrant0543664 · Answer

The 10s is for the sound to go from the first submarine to the second, the total distance the sound waved travelled from the first submarine to the second and back to the first is 30km=30000m therefore doubling the time to 20s just like @peachpi had stated