# free fall

### (OT) What happens when you drop your video camera

Not related to anything really, but I find it a good laugh when this GoPro camera falls out of an airplane.  There are a couple of surprising things... Just because it's Friday. Note: It seems there is some skepticism as to whether this is real or not, I personally don't find anything implausible about it if you can accept the unlikeliness of it specific landing spot...

### Star Trek Space Jump

While I am still fresh on the Space Jump topic, let me take it to the extreme. Star Trek extreme. SPOILER ALERT But really, is this a spoiler alert if it is from the trailer of a movie that has been out forever? Of course, I talking about the latest Star Trek movie where three guys jump out of a shuttle and into the atmosphere. So, in light of the Red Bull Stratos jump, how would this jump compare? First, my assumptions: This Star Trek jump is on the planet Vulcan. I am going to assume this is just like Earth in terms of gravity and density of air. The jumpers in Star Trek have on stuff…

### Stratos Jump for Mere Mortals

Crazy, but I was on CNN Saturday night. They contacted me at the last minute to talk about the Red Bull Stratos Jump. Here is a screen shot to show that I am not making this up (or that I have awesome photoshop skillz). Looking back, maybe I looked like an idiot. Really though, it wasn't my fault. I thought we were going to talk about physics. The first two questions threw me for a loop. Here are the two questions and my response (roughly paraphrased): Will Felix survive the jump? Answer: I guess so. Is there a scientific reason for this jump? Answer: I thought we were going to talk…

### Another example of a dangerous jump

Check this out. So, the guy jumps from 150 feet into some cardboard boxes. Why are the boxes important? You want something that can stop you in the largest distance to make your acceleration the smallest. Here is my Dangerous Jumping Calculator. Basically, you put in how high you will jump from and how much distance you will take to land and it tells you your acceleration. You will probably need this G-force tolerance info from wikipedia. One problem - this calculator doesn't really work for this case. It doesn't take into account air resistance. Does air resistance even matter in this…

### Faster than terminal velocity

I had so much fun creating graphs for the Red Bull Stratos Space Jump calculation, that I figured I should make some more. Can you fall faster than terminal velocity? That is the question. Air Resistance Air resistance is a force exerted on an object as it moves through some stuff - air in this case. The magnitude is usually modeled as: Rho is the density of the stuff the object is moving through A is the cross sectional area of the object C is the drag coefficient of the object - this depends on the shape (a cone would be different than a flat disk) v is the magnitude of the velocity of…

### Stratos Space Jump

Red Bull is sponsoring this sky dive from really really really high up - Stratos: Mission to the Edge of Space. Seems dangerous. The basic idea is that Felix Baumgartner will take a balloon ride up to 120,000 feet and jump out. Here are some questions: Will he reach supersonic speeds? The Red Bull site says: "can Felix react to a 35 second acceleration to mach 1?" How about the claim that he will free fall for 5 minutes and 35 seconds? That seems pretty short. In 1960, Joe Kittinger jumped from 102,800 feet. Will 20,000 feet make a large difference? Assumptions Clearly, this can be a…

### More Examples of 'Weightlessness'

Jennifer over at Cocktail Party Physics has a nice post about her trip to Disneyland. The one ride that would be fun to play with (in terms of physics) would be the tower of terror. Think of the cool things you could do with a video camera during that ride. It would be like a mini-vomit-comet. Anyway, I want to talk about one part of Jennifer's post. "As one would expect, this lifted us out of our seats slightly, as much as the straps would allow, and we got that one glorious moment of seeming weightlessness, before reaching a jerky stop and being raised back up for another drop." It is…

### Can an iphone tell you if your parachute does not open?

Here is another one from a great podcast - Buzz Out Loud. I totally can't remember which episode it was, I listened to a several in a row mowing the lawn and doing outside type work. Anyway, the discuss was along the lines of: Could an iphone tell if your parachute didn't open with its accelerometer? The first and simplest answer would be "no". When you are skydiving, you quickly reach terminal velocity such that you are no longer accelerating. Maybe the built in GPS could use elevation data, but it seems like that is rarely used (and not very accurate). There is perhaps a way that work…