While he was safely and securely belted into the helicopter, Mark and the helicopter both were traveling horizontally at 15 m/s.
After he foolishly unbuckled his safety belt, stood up, opened the hatch, leaned out, and 'accidentally and surprisingly' fell out, there was no horizontal force on him (we're assuming NO air resistance), so there was nothing to change his horizontal speed, and it remained a constant 15 m/s as he fell.
So after 2 seconds, when he splashed down, he was <em>30 meters</em> ahead of where he hazardously, clumsily, and foolishly fell out.
Since he spent 2 seconds falling, we can also easily calculate that he fell from a height of 19.6 meters (about 64 feet), and his velocity when he hit the water was 24.7 m/s (about 81 feet per sec, 55 miles per hour !). That kid is lucky to be accidentally alive ! Hopefully, he never goes anywhere near a helicopter again from now on.
= = = = =
Now that we're all horrified and trembling from the sheer terror of this story, we can all relax and smile. The story is impossible !
If there's no air resistance, then the helicopter can't fly.
And if there IS air resistance, then Mark doesn't hit the water with quite so much velocity, and he has a better chance of survival that what I've calculated here.
Furthermore, nobody could actually be that foolish. I mean, how does anyone '<em>accidentally</em>' fall out of a helicopter ? !
