A stone is dropped into a deep canyon and is heard to strike the bottom 15s after release. How deep is the canyon? The speed of sound waves in air is 343 m/s and the acceleration of gravity is 9.8m/s^2. Answer in units of m.

Answer 1

td= time down
ts=time for sound to come up

td+ts=15

depth= 1/2 g td^2
td= sqrt 2depth/g

ts= depth/343

15= depth/343 + sqrt 2depth/g

let x= sqrt depth
x^2= depth

solve the quadratic.

Answer 2

26