The Fugitive Dam Scene - Could Harrison Ford actually survive?

[StealthSilver]

"The Fugitive" Dam Scene - Could Harrison Ford actually survive?

Homework Statement

For my mechanics class, I've been tasked with "debunking" an example of bad physics from a movie. Alternatively, I can prove what appears to be an example of bad physics from a movie, but is actually good physics. The teacher wanted us to submit our movie ideas early, so I chose the scene from The Fugitive, when Harrison Ford's character jumps off a dam and miraculously survives.

Here is the scene if you haven't seen it.

https://www.youtube.com/watch?v=g5RRjdhbxPk 2. The attempt at a solution

After doing some research, I found that the Cheoah Dam was used to film the exterior shots for the movie. According to Wikipedia, the dam is 69m tall. In addition, I looked up the average mass of an American man, which is 86.6kg (again, according to Wikipedia).

Using this information, I understand that calculating the velocity, kinetic energy, etc. of the falling Harrison Ford would be trivial. However, my problem is more theoretical.

While it is clear that hitting, say, a concrete floor from that height would clearly kill Harrison Ford's character, I'm not sure what effect the water itself plays.

Could it be possible that the falling water from the dam could somehow allow Harrison Ford's character to survive? Also, are there aspects in regards to the way that the scene itself is filmed that I could prove to be inaccurate?

Any help regarding this problem would be much appreciated. Many thanks in advance!

 

[Mike Pemulis]

It's not so easy to answer this question from first principles. Why don't you look up real-life examples of people falling into water from similar heights? I think a lot of people have gone over Niagra Falls in barrels and survived, for example. And sadly many people commit suicide by jumping off famous bridges like the GW and Golden Gate. There are probably records of numbers of jumpers and survival rates somewhere. Once you find those, you can try to find factors that contributed to jumpers surviving -- posture, body type, wind, and so on.

 

[I like Serena]

I've read about people jumping from bridge and as I've understood it, the largest impact is when the surface tension of the water must be broken.

However, in this dam example, I think the surface tension is already broken by all the spattering water, so I think it would be easier to survive, as long as you don't hit a rock or something under the water.

 

[Borek]

He is moving with water, so he is not just hitting the surface. Also even if he hits the dam wall, he hits it at such an angle that he will bounce, which means much lower forces acting on the body.

World record if cliff diving is around 54 meters, so not that far from 69.

 

[StealthSilver]

That is very interesting. I did not notice the bounce at all. I could, for instance, calculate the post-bounce velocity using momentum.

However, as a physics newbie, I am unsure as to how much force it would actually take to kill a man.

 

[Borek]

I am not saying he bounced, I am saying "even if".

 

[turbo]

Considering that he is falling with a considerable amount of water, and that water is entraining air into the water at the bottom pool, there may be an opportunity for a more gentle impact than one might expect. I used to do a lot of white-water kayaking, and water with a lot of entrained air is not very buoyant. It can also be difficult to execute a proper Eskimo-roll unless you are used to heavy white-water because that foamy water doesn't provide much resistance against your paddle-blade when you make your sweep. Need a good sweep combined with a well-timed hip-snap to pull it off.

 

[StealthSilver]

Having calculated the probable velocity when he hits the water (around 36m/s), I was able to count the frames, giving me the amount of time it takes him to decelerate once he goes under.

Using this, I found the impulse to be 3186Ns. Would this be realistic to survive?

 

[Idoubt]

I think a problem here is its hard to define a "survivable" impulse, the human body is very complicated and its surprising what it does and does not survive.

Using the frames per second to calculate the impulse throws off the rest of your calculations, since that shot was probably done with someone just jumping into the water and not from such a large height.