1. The problem statement, all variables and given/known data Your mobile phone drops down a sinkhole. You hear it hit the bottom 8.5 seconds later. How deep is the hole? Assume there is no air resistance velocity of sound 334m/s gravity 9.8m/s 2. Relevant equations 3. The attempt at a solution I tried integrating the equation using just the acceleration; however, I believe that the velocity of sound needs to be incorporated aswell. So I started with a(t)=9.8 then integrated to get 9.8t +c, then I made t=0 v=0 and so c=0 and integrated again to get 4.9t^2 +c, I'm not sure where to go from here.