1. The problem statement, all variables and given/known data A rock is thrown downward into a well that is 9.17 m deep. If the splash is heard 1.15 seconds later, what was the initial speed of the rock? Assume the positive y-axis to point upwards 2. Relevant equations Time of sound(Ts)= Distance/(343m/s) Time of stone(Tf)=Total time - Time of sound Vo=(Height Final - Height Initial)/Tf - 1/2 x g x Tgiven 3. The attempt at a solution 1.So basically I started off by finding the time it takes for the sound of the stone hitting the water to reach my ears (Ts): So i took the depth of my well divided by the speed of sound through air: 9.17m/(343m/s)=.026735s 2.Next i subtracted .026735 from the total time to find out how long it takes the rock to hit the water at the bottom of the well (Tf): 1.15s-.026735s = 1.12327s 3. Next using this new time (Tf) i try to figure out velocity, and this is where i think my math is getting screwed up, because i can't get the right answer. Here is my process: Using the formula Vo=(Height Final - Height Initial)/Tf - 1/2 x g x Tgiven Vo=(0-9.17m)/1.12327s - (.5)(-9.81m/s^2)(1.15s) The answer i get is -2.523m/s, which is not right. I am fairly certain the velocity should be negative, since the rock is traveling in the negative direction according to the Y axis parameters given, but other than that i don't know what other mistakes i might be making. I think my formula for step 3 might be slightly off, but i'm not sure where i'm making my mistake. Big thanks in advance for any help anybody can offer!!