# Silencer

Senior Members

396

1. ## Use of Calculus in Electrical Engineering

I am doing a project for my calculus class in which we give a presentation about a career that utilizes calculus. I chose Electrical Engineering. Can anyone provide some examples of how EE uses calculus? I know a lot of formulas are used, but I'm sure some of these must have been derived using calculus. Aren't Maxwell's Equations used in EE? A few examples or just general cases that I can research further would be helpful. Than you!
2. ## Will a mix of hydrogen and oxygen float a balloon?

The latex balloon can also melt from the explosion, causing droplets of hot plastic to be flung at you.
3. ## Tea Popsicle

They must put a chemical in to stop the separation, or they flash freeze it.
4. ## Tea Popsicle

One day this week I made some tea and put sugar in it. However, it was really hot and I was in a hurry so I put it in the freezer to cool it off a little. Well, I forgot about my tea and found a tea popsicle in my freezer, complete with a spoon handle. Well, it tasted pretty good, except that the top (part closest to the handle of the spoon) was really sweet. I was wondering what happened to the solution as it cooled. Did the sugar all rise to the top and start to crystalize as the solution cooled? Also, when I managed to get it out of the mug it almost immediately began dripping. It was sort of like the tea was draining from from the ice. So I'm just curius as to what happens when you freeze solutions. It might be nice to make a tea popsicle that is evenly sweetened throughout if possible.
5. ## aerogel

Look at the picture with the crayons. That's wild.
6. ## Gas Bubbling Through Water

...really descriptive title, I know. I was wondering about the physics of devices in which air bubbles pass through a liquid and then out again. I got to thinking about a straw, and how the water is moved through the tube. You have two openings, one in the cup which is really big, and then the end of the straw which is really small. If you reduce the pressure on the straw end the water gets pushed up the tube by pressure on the other end. But what if you reduce pressure on the cup side? It seems that the air will bubble through the liquid and out. Is this because there isn't enough pressure to push all the water out? My question is how you can tell whether the air will bubble through or whether the water will move, and if it will bubble, how much pressure will be required to make that happen. I hope that my question is clear enough. I'll try to clarify as requested.

whoops
8. ## Natural Gas

This is a slightly related anecdote. I'm not sure how my brother heard this story. A large natural gas main was broken and literally wailing gas. The fire department was all around pretty much just keeping people away and letting the gas company people do there thing. A guy from the company walks up with a lit cigarette and just tosses it into the gas pipe. It extinguishes. Meanwhile, the firemen were shitting their pants. He says, "ehh, it needs to oxidize first before it can burn." True? Who knows. but it was amusing.
9. ## Calculus: Limits

Let $f(x) = (1 + \frac{1}{x})^{x}$ a. Find the domain of f. b. Draw the graph of f. c. Explain why x=-1 and x=0 are points of discontinuity of f. d. Are either of the discontinuities in part c removable? Explain. e. Use graphs and tables to estimate $\lim_{x\to\infty} f(x)$ I don't really know how to do a. There are a lot of values between -1 and 0 that are undefined. B and C are easy enough. D I have trouble because I don't know how to find the limit with the exponent. Would substitution be valid? And e I can handle. Thank you!
10. ## Making Sodium Iodide

You switch from first to third person a lot. Neat experiment, though.
11. ## Simple Ice Bomb = WMD? Is it possible

How do you determine how "strong" something is when it freezes? If the pressure was great enough, could you stop it from freezing?
12. ## Does food lose its spiciness if you freeze it?

Breakdown of the capsaicin? Just heat it up and throw in some chili pepper.
13. ## Very powerfull shock wave..

^why is that?
14. ## Very powerfull shock wave..

The molecular formula for water is H2O. That's two hydrogens and one Oxygen. The reaction for creating water by exploding H2 and O2 together is 2H2 + O2 -> 2H2O That means that for every molecule of oxygen you need two of hydrogen. Since you're working with gasses that will be under the same pressure and temperature, you know that equivalent volumes will also have about the same number of molecules. So it's really 2 parts hydrogen and 1 part oxygen. However, you should probably take YT's suggestion and use equal parts, that way more of the balloon will be consumed and you won't have hot bits flying everywhere.
15. ## Hazards of PVC

Do you live in America? If so, contact your local code enforcement or police department and report what happened. You should also probably go to a doctor.
16. ## most corrosive liquid/gas come one come all to share your opinions

I imagine that liquid sodium would be pretty rad.

Ah, ok. Thanks.

While we're on the subject, could someone actually explain what's happening chemically when you turn such chemicals into salts? Like, on prescriptions it's always "blahblah HCl" or "blahblah HBr" or something.
19. ## New Periodic Table?

apparently it groups certain atoms with similar characteristics better than mendeleev's table.
20. ## separating carbon dioxide from biogas

What, exactly, is biogas?

http://www.erowid.org/plants/coca/coca_chemistry.shtml You will see the melting points for various forms there.
22. ## Can someone please explain why

This is actually more of a question for the medical sciences, since you want to know how chloroform affects your brain cells.
23. ## New Periodic Table?

It's interesting. Go to the slide show and just skip through until it shows you the picture of the new periodic table (the other info in the slide show will be very mundane to you). http://www.slate.com/id/2122919?nav=wp
24. ## Magic bullet.

First, living in Canada has nothing to do with gun knowledge. You think that all Americans are crazy gun nuts or something? There are plenty of hunters and gun enthusiasts in Canada...
25. ## Different thermites

Doesn't the etcha sketch work with magnets? Aluminum isn't magnetic...
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