Splat

On November 2nd, 1987 two skydivers from Chicago wanted to have a little Halloween fun. They decided to jump from an airplane, and if that wasn’t fun enough, they did it with a pumpkin. The two skydivers than started to pass the pumpkin between the two of them over half a kilometer in the air. This was all fun and games until the last skydiver decided to open his chute, when he did this the pumpkin was immediately ripped from his arms. It than plummeted thought the roof of a Chicago home and splattered to pumpkin pieces all over the newly remodeled kitchen.

But, you maybe be wondering why would the pumpkin be ripped from the skydivers hands so viciously? When the divers jumped out of the plane they eventually reached a point without acceleration and where able to stay at a constant speed, this is called terminal speed, this allowed the skydivers to be able to toss the pumpkin back and forth. The pumpkin was ripped away because when the skydiver opened his parachute there was such a great upward force on him that the force ripped him away from the pumpkin, the parachute was just doing its job though. The parachutes job is to create a greater upward force on the skydiver to reduce the divers downward velocity.

If you think about it though this happens all the time, not just when passing pumpkins back and forth while plummeting towards the earth. When a child is holding on to a small toy, and an adult comes along and suddenly grabs the child and lifts it up with a great force, the object that was in the child’s hands will be ripped away due to the same factors that happened with the pumpkin and the skydivers. That child is having a greater force pulling up on him that is reducing the downward gravitational force. So, the next time you decided to jump from a plane with a pumpkin, make sure you have a good grip.

Hoston, R. L., and J.W. Kaman, “ On Parachutist dynamics,” Journal of Biomechanics, 14, No.9, 645-652(1981) - The easiest way to find this journal is by putting in the name and date of the journal into any internet search engine. This article talks about biodynamic modeling and in investigations of the dynamic behavior of bios stems. It also examines the dynamic response of the human body in a crash event and assesses the injuries sustained to the occupant’s head, chest and pelvic regions. This article was very helpful when trying to understand the way that the body reacts when parachuting. There was a lot to this article that was not relevant to my topic, but over all it was very helpful. This article was very credible because, it is out of a peer reviewed journal.

Wagner, G., and Wood, R. “Skydiver survives death plunge' (and the physics that helped),” Physics Teacher; Dec96, Vol. 34 Issue 9, p543, 3p, 2 diagrams, 1 graph, 1 bw - The way that I found this article was by using EBSCO host. This article is about how physics helped save the life of a skydiver with a parachute failure. This article talked about application of terminal velocity concept, factors affecting terminal velocity, function of impulse-momentum equation and factors affecting the chances of survival. This article was very helpful to me because it put not just the physics into better perspective, but also the danger that was involved in my original article. This article was very relevant to my topic because, it talked a lot about the physics that was involved in the parachuting accidents, as well as things that can happen while parachuting. This article was not as credible as the first because it was not peer reviewed, but the content of the article all was accurate and correct.

Dr. Eric Christian, “Can a Parachute Pull You Upwards After You Start to Fall?” http://helios.gsfc.nasa.gov/qa_gp_ev.html#parachute, (October 2008) - The best way to find this article would be to go directly to the NASA website. This website was very interesting to me. Not only did it have information, it also had useful pictures. They also talked about in this article other factors that the previous articles did not ,like gravity, friction, and even the skydivers harness. This article also talked about why a parachute pulls you upwards after you start to fall. In this article they talk about the stretching of the harness then pulls the skydiver upward relative to the parachute, maximum upward velocity relative to the parachute at the point where the harness is at its natural length, a persons terminal velocity, and how friction and gravity come into play. This article was very relevant to my paper because it helped me learn more about terminal velocity and what happens when you open a parachute. This article is credible because it is straight from the NASA website.