Hey, I Know How High It Went!

I figured there's got to be a way to calculate the altitude effectively. I thought it might have something to do with the descent, since the factors are more controlled than on the ascent (variable thrust hence variable velocity hence variable drag hence calculus). The answer was terminal velocity. Solve the drag equation for velocity, and call the drag mass x gravity since the rocket is in equilibrium. The result is the following equation:

v = [(2mg)/(pACd)]^(1/2)  (I hate typing math. It always looks like someone just puked jibberish)

where v = velocity, m = mass of the rocket (0.550 kg), g = gravitational acceleration (9.8 m/s/s), p = the atmospheric density (1.2 kg/m^3 at the time), A = the area of the parachute (0.164 m^2), and Cd = the drag coefficient for our parachute (0.75 for a flat sheet). Plugging it all in yields v = 8.54 m/s.

I then went back to the video and timed the descent, which turned out to be 21 seconds. Using d = vt I was able to figure the rocket fell from 179 m, or 574 ft.

It is important to realize that this wasn't the maximum altitude the rocket reached, it was simply the point where the parachute popped out. The rocket may have fallen from a hundred or so feet beyond that.

If anyone finds a problem with any of my thinking, please let me know.

Figure 1

Forces of drag and gravity are in equilibrium (Net force = 0)

November Is a Lot of Things... But Not Rocketry Month.

I haven't written a post in a while, because I've been far too busy with a lot of things on my plate.

One of those things is my honors algebra 2 class, where I have been studiously learning the finer points of higher-level math. It is a very important subject to have under your belt if you're going to be an aerospace engineer.

Another thing that I have been involved in is NaNoWriMo, which is the short way to say "National Novel Writing Month." The goal is to write 50,000 words in one month, but I've set my goal to 100,000 OR to finish my novel, whichever comes first. If you could sum up the whole story into one sentence, it might go something like this: "An aspiring aerospace engineer foils the enemy's plot to control the planet." It's science fiction, as you may have already deduced. I don't claim to be an excellent writer or anything; this is just an event I participate in for fun. And it runs a common theme with one of my main ambitions, namely the exploration of the skies and beyond.

One other thing I'd like to mention is Embry-Riddle Aeronautical University. It's a college down in Arizona that has sparked my interest, and has an aerospace engineering program that matches perfectly what I've been looking for. I still have a couple years before college, but I've started to think about it now. I also might look into the U of MN's aerospace engineering program, I've heard that theirs is pretty good, and it's much closer.

So my current rocket hasn't even been looked at in the past month or so, since my life has been taken up with so many other things. But High-5 will get lots of attention in the months to come.

I just thought that I would post this to let you know that I am still blogging!