We recommend that you avoid doing this jump at God's Bath. These guys have done this jump before and are in top shape. Jumping from cliffs is dangerous and can put your life and health at risk. Never jump without checking your landing first. Here is what these guys faced doing this jump.
From the video, I timed the amount of seconds in the air by stop watch = 1.17 seconds. I fudged a few tenths of a second to cover the time in the air below view.
Velocity = Distance/Time
Acceleration = 9.8 m/sec2 (gravity)
Vo = 0
VF = Vo + aT
Solving for VF we get 11.46 m/s
or 25 mph
plugging in the top equation I could figure out the relative height of the cliff.
We know VF = 11.46 m/s
Time = 1.17 seconds
Distance = 13.40 m or about 45 feet. Using error and significant digits I would expect:
Cliff height = 45 to 50 feet !
Velocity = 25 to 30 mph!
Be Careful!
Force = Mass x acceleration
It only takes 9lbs to break a bone. Each person is different based on tendons and muscles to cushion the fall. Based on this jump there is about 846 Newtons of force on two legs or about 190 lbs of force (80 lbs per leg). That's about 10x the amount to actually break the bone.