i need help with this problem. i've tried for a while now and it is driving me crazy! i've tried about everything including using what little calculus i remember from last year! please help! the problem is: you are standing on a cliff and you drop a rock straight down, neglecting air resistance. you hear the rock hit the water 3.4 seconds later, if the speed of sound is 340 m/s, how high is the cliff. i would greatly appreciate any help, and as i have hit 2 or 3 dead ends that filled sheets of paper, i see it as pointless to put it on here. just trust me when i say i need a little insight. i tried to set it up as such: t = delta X / V = sqrt(2 deltaX/g) is there any truth to this equation?