Hello everyone, I am a just now starting to study physics and I am quite the newbie, but I am loving it! I am not doing this for school, I study as a hobby in my spare time, but I imagine this is the right place to post this exercise anyway! Here it is: We have a rock dropped from a cliff that falls in the ocean, and after 3.2 seconds, we can hear the splash of the rock into the water. We are looking for the height of the cliff! So, we have: t = 3.2 s (total time) g = 9.80 m/s2 v of sound = 340 m/s (or -340 m/s if we put it in the same equation as the rock, perhaps?) v0 of the rock = 0 m/s Using the formula for constant acceleration, we can easily find the height of the cliff while ignoring the time it takes for the sound to travel from the water back to the person that threw the rock: x = x0 + v0t + 1/2at2 (I am using x instead of y for convenience, even though the more commonly accepted one here would probably be y) since x0 = 0 and v0 = 0, the equation ends up being x = 1/2at2 and when we solve it we get the answer x = 50.176m The obvious problem is that the time for the rock to fall is not t, it is actually t - t2 (t2 being the time it takes for the sound to return), and I am finding it hard to figure out an equation that would combine all the information I have (which is not much) in one and give me the correct answer. I was thinking about a lot of possible solutions, for example using the fact that the sound and the rock are both traveling the same distance (x0 to x and then x to x0), but no luck so far. Please help!