Science Forums: mooeypoo - Viewing Profile - Science Forums

Hi guys,

I had a discussion with a friend about the Harrier jet and how far up it could go compared to the propulsion of the jet, and if we could calculate this mathematically.

Before I go on, the Harrier jet is a pretty cool attack plane that can lift off vertically. See example here:



Theoretically speaking, if instead of gas propulsion we had water jets going downwards (powerful ones) and we know the weight of the jet, we should be able to calculate at what distance above the ground the forces of the thrust from the propulsion equals the force of gravity from the plane's weight. So we could tell how far up it would go based on the initial pressure out of the nozzle.

I know this is possible to calculate, I'm just having trouble implementing this. How would I go about calculating it? If I want to build my own small model with garden hoses and a tiny jet (on a little plate or something), I would then have the exact pressure out of the nozzle of the garden hose, and the weight of the model plane + plate, how would I calculate how far up the model plane would go?

I'm a bit confused, I'm not sure how to start this. Bernoulli's equation doesn't seem to help because it requires an enclosed flow and this is not one of those, so I went with jet propulsion equations, like in this resource form NASA. But that seems to speak about horizontal propulsion, and not quite about vertical one.

Any help? If we know initial pressure from the nozzles and weight of the model plane, how do you start calculating the equilibrium equation?

Thanks!

~mooey

I am looking around for graduate programs to plan my Master's / PhD. My interest is space research, and I'm still getting my bearings in it. I'm thinking exoplanetary research is really interesting, but so is radio astronomy and/or instrument design.

What I noticed, however, is that schools offer two types of degrees in general: Astronomy and Astrophysics.

It seems to me that astrophysics is "categorized" under "Physics" while astronomy is its own category. When I asked some professors about the difference, it struck me that the answer depends on their orientation. Physicists tended to lower the value of the astronomy degree(s) and astronomers told me the difference is mostly about concentration.

I can't believe astronomy is "simply" "collecting data". I know astronomers that do more than that.
On the other hand, I can't believe the division is about "theoretical" and "experimental" since I saw a few graduate degrees that offer experimental astrophysics and others that have theoretical astronomy. The division, then, is different.

Quite a lot of sites also divide them up either by departments ("Astronomy" and "Physics" are different departments, and astrophysics is under physics) or by categories. "Physics and Astronomy" sounded to me as repetitive at first, but apparently it's not....

So... what's the difference?

How do I know which program to look for? Do I really "compromise" if I go for astronomy on the "expense" of physics? Do I stop being a physicist is I take "Astronomy" grad program (while I keep being a physicist if I take the 'astrophysics' one?)

This is all very confusing...

Thanks!

~mooey

Hi guys,

So, I graduated with a physics degree and research honors. In my research I was heavily involved with modelling, particularly with mathematica and matlab. I am also a relatively proficient php/mysql programmer and I have a good grasp in jQuery, AJAX and developing CMS extensions.

I have a few small projects under my belt, most are small jquery and relatively small CMS extensions. I program for fun, and I have been doing that since around 6th grade. I'm starting out in Perl now, and its a pretty smooth ride so far. I also took a C++ course in college (waste of time though.. very veeeery basic)

Problem? I have no official programming education. I want to try and get a job with some programming in it, since I do know it well, but I'm not sure I can get anywhere without some sort of proof of knowledge. Also, my experience is halfassed. I program alone to get a resul, so I am less familiar with the core workings, security standards or standards in general, other than what I am reading as I go along.

Now that i've graduated, I have time to take extra courses, or study for a certificate. I was thinking about the Zend PHP5 one, but from my research, many claim its useless.

Should I go for a particular certificate? What should I have in my resume to get the attention of programming oriented companies? My physics degree is a strong proof for math, algorithms and modelling, does it help?

Thanks

~mooey

I thought I'd post a heads up, there's going to be an AAPT meeting in Ontario, California Feb 4-8. It should be a great place to discuss science education with emphasis on physics to all ages.

There are sessions about AP Physics, Animation Physics in Hollywood, Best Practices about Increasing the Number of Women in Physics, Outreach, Pre High school, etc etc. It's a great convention for anyone interested in physics and science education.

Also, I will be delivering a short (and hopefully very good) lecture titled "Developing Extension Activities for APS PhysicsQuest: Inquiry-based Learning" which is based on my experience in my internship in APS Outreach during the summer.

If anyone plans to go to the meeting, my lecture is at 8am Monday morning (bring coffee so you don't yawn...)



You can find abstract and details here: http://aapt.org/Conf...essionpanel.cfm


See you there!

~mooey

As usual with pop-media, the title is a tad bombastic; the effect seems to be that the brain takes less processing time with nude bodies than it does with clothed ones, which I guess makes a lot of sense. There's less to analyze.

Still, it was too good not to share.

http://cnews.canoe.c...3/19013771.html

Quote

If anyone can find the original science study, I will be happy to stare at it.