A geological survey ship mapping the floor of the ocean sends sound pulses down from the surface and measures the time taken for the echo to return. How deep is the ocean at a point where the echo time (down and back) is 7.07 s? The temperature of the seawater is 25°C. Find the answer in km 7.07 / 2 = 3.535 seconds to get from surface to ocean bedrock. v = 331 + .6*25 = 346 m/s 3.535 * 346 = 1223.11 m ==> 1 223.11 meters = 1.22311 kilometers This is wrong according to the online homework I'm doing?