You are approaching Chatham Strait from the south in foggy weather. You have Coronation Island and Hazy Islands on the radar. Suddenly the radar malfunctions. You then resort to using whistle echoes to determine your distance off Coronation Island. Your stopwatch reads 16.3 seconds for the echo to be heard. How far are you off Coronation Island?
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Memory is as foggy as the shore.
If my memory serves, sound travles at 1100 ft. per second. Having to travel both directions, you would divide the 16.3 in half and have 8.15 seconds from the shore back. That would mean you are 8,965 ft from the shore. Of course if my memory doesn't serve, I would be wrong.
If my memory serves, sound travles at 1100 ft. per second. Having to travel both directions, you would divide the 16.3 in half and have 8.15 seconds from the shore back. That would mean you are 8,965 ft from the shore. Of course if my memory doesn't serve, I would be wrong.
speed of sound
The speed of sound in dry air at 25 deg C (77 deg F) is 1132.3 ft per sec. In fog, (moist air) it is considerably faster.
The speed of sound in dry air at 25 deg C (77 deg F) is 1132.3 ft per sec. In fog, (moist air) it is considerably faster.
You are about 9000 feet from a reflecting surface
now if that happens to be close to the shoreline you have a good idea where the island is, But if that reflecting surface is a half mile inland then you have misleading knowledge.
now if that happens to be close to the shoreline you have a good idea where the island is, But if that reflecting surface is a half mile inland then you have misleading knowledge.
Good answers
The answer is 1.5 miles, which I believe is 9114.17 feet. Question comes from the general navigation part of the CG exam.
The answer is 1.5 miles, which I believe is 9114.17 feet. Question comes from the general navigation part of the CG exam.
Data is missing from the question *o
"The speed of sound is dependent on the density of the air...and the density of the air is dependent on the temperature of the air." If the time was 16.3 seconds for a round trip, the time is 8.15 seconds one-way. If the answer is 1.5 mile = 7920 feet, then calculating the speed of sound. 7920 feet/ 8.15 second = 971.779 f/s For sound to travel at this speed through air, the air temperature is -66 degrees Fahrenheit. If the answer is 9914.17 feet, then calculating the speed of sound. 9914.17 feet/ 8.15 second = 1118.30 f/s For sound to travel at this speed through air, the air temperature is 61 degrees Fahrenheit. No data was given for what the air temperature. Fair Winds, Clyde
"The speed of sound is dependent on the density of the air...and the density of the air is dependent on the temperature of the air." If the time was 16.3 seconds for a round trip, the time is 8.15 seconds one-way. If the answer is 1.5 mile = 7920 feet, then calculating the speed of sound. 7920 feet/ 8.15 second = 971.779 f/s For sound to travel at this speed through air, the air temperature is -66 degrees Fahrenheit. If the answer is 9914.17 feet, then calculating the speed of sound. 9914.17 feet/ 8.15 second = 1118.30 f/s For sound to travel at this speed through air, the air temperature is 61 degrees Fahrenheit. No data was given for what the air temperature. Fair Winds, Clyde
Clyde, for practical purposes
sound travels about 1100 feet per second. They also didn't mention the duration of the sound signal, the condition of the shoreline. The essence of the question was do you have any idea how fast sound travels? Whether the exact values are 1100 or 1129.3758945 feet per second is inmaterial for this question. You really want to know if you are 1/2 mile off shore or 3 miles off shore or some value in between. In days past, men would fire a rifle and listen for the echo. A big drum also works. My statement concerning the location of the sound reflecting structures on the island can play a part in the accuracy of the answer. Hay fields that are quite flat won't reflect sound as a forest will and a forest won't reflect sound as a cliff will. so if you stated that you are 8,957 feet of the island you would be wrong because you can't posibly know where the sound was reflected.
sound travels about 1100 feet per second. They also didn't mention the duration of the sound signal, the condition of the shoreline. The essence of the question was do you have any idea how fast sound travels? Whether the exact values are 1100 or 1129.3758945 feet per second is inmaterial for this question. You really want to know if you are 1/2 mile off shore or 3 miles off shore or some value in between. In days past, men would fire a rifle and listen for the echo. A big drum also works. My statement concerning the location of the sound reflecting structures on the island can play a part in the accuracy of the answer. Hay fields that are quite flat won't reflect sound as a forest will and a forest won't reflect sound as a cliff will. so if you stated that you are 8,957 feet of the island you would be wrong because you can't posibly know where the sound was reflected.
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