We came across this shaft in the west desert of Utah and decided to drop some rocks down it and see how long it took to hit the bottom.

We determined that a rock falls at 32.2 ft/sec. and increases by that amount every second of free fall until it reaches terminal velocity (which based on the diameter of our rock would be around 170’/second.  So the breakdown of how far it fell per second is below:

1st second:  32.2′
2nd second: 64.4′
3rd second: 96.6′
4th second: 128.8′
5th second: 160′
6th second: 170′ (terminal velocity reached)
7th second: 170′
8th second: 170′
9th second: Time it took for the sound to reverberate back up the shaft
Total feet the rock fell in 9 seconds – 992 feet!!