A sonar is used to find the depth of the sea. Four seconds after the sound leaves the sonar is returned. Because of the reflection from the bottom. If the speed of the sound in water is 1460m/s the depth of the water is:

Explanation

The key to solving this problem is understanding that the 4 seconds given in the problem is for the entire round trip of the sound wave, meaning the time covers both the journey to the sea bottom and back up to the surface. Given the speed of sound in water is 1460 m/s, the total distance covered in 4 seconds is 1460 m/s * 4 s = 5840 m. Since this is the round trip distance, the actual depth is half of this distance, which is 2920 m. Options A and D incorrectly calculate the distance by not properly considering the round trip nature of the journey. Option B assumes all 4 seconds are used for a one-way trip, which is incorrect.