# Finding distance using sound

1. Oct 3, 2005

### babbagee

here is the question

Cliff Height. You are climbing in the High Sierra where you suddenly find yourself at the edge of a fog-shrouded cliff. To find the height of this cliff, you drop a rock from the top and 10.0 s later hear the sound of it hitting the ground at the foot of the cliff.

Ignoring air resistance, how high is the cliff if the speed of sound is 330 m/s

ok i did the problem and i just wanted at least to people to check my work.

h = .5gt2

time for sound to reach the person
ts = h/vsound

since the total time is ten seconds then i can solve both equations for time
time for rock to hit ground
t = sqrt(2h/g)
time for sound to travel up to the person
t = h/vsound

then ttotal = sqrt(2h/g) + h/vsound

then i can solve for h.

I got -1086.9m and -14130.43m

can at least two people confirm that. The reason i am asking is because I am doing my homework online and i have one more try to get it right, so i want to make sure I got it right.

Thanks

2. Oct 3, 2005