Problem: A swimmer sees a parachutist hit the water and hears the impact twice, once through the water and the second time through the air, 1.0s later. How far from the swimmer did the impact occur. Vs of air is 340m/s. Vs of water is 1400m/s and the answer in the book is 450m. 2. I know this is a simple rate question, except I cannot get it! VT = D 3. I attempted to do VT = D and just sub in the velocity values for each, but it just gives you the same answer as the velocity of course. ex of what i tried to do: 340m/s x 1s = D, D = 340m, doesnt work.