A man drops a stone into a water well on his farm. He hears the sound of the splash 3.89 s later. The acceleration of gravity is 9.8 m/s2 and the…

A man drops a stone into a water well on his farm. He hears the sound of the splash 3.89 s later. The acceleration of gravity is 9.8 m/s2 and the speed of sound in air is 312 m/s. How deep is the well?