Steadiman

I've noticed that most of my shop motors all turn at about the same speed....say 3500rpm. Some run at about half of that. And I've noticed that some motorized gyros that I have (for photography) run at very high speeds of 20,000 rpm but require and inverter that converts to 400Hz. Also, they take a long time to get up to speed. Is that related? My grinder motor hits speed in a couple of seconds. Can anyone explain the nature of all this? Why don't motors run 800 rpm or 9600 rpm? And what is the story with routers? They are very high speed but I think run on 60Hz. Electrical engineers out there.....give it to me in laymans terms?

I'm gonna do a little demo at my son's school with liquid nitrogen and its interesting cryogenic properties. I'm not a teacher but it's one little way that I can contribute to education. I will go over some very basic chemistry (6th graders), freezing things like marshmallows and roses, blowing up water bottles, and making LN ice cream (the big finale). I have done this before with tremendous success but I'm looking for some additional ideas to make the presentation even better. You scientists out there....got anything for me?

I've got a cheap Dell computer that has an integrated graphics board. It's the 82945G Express Chipset Family. It is pretty wimpy when it comes to running games. As luck would have it, there are many games that do run well that my children play. However some of the more serious games (like Bioshock) will not run. What's the best way to upgrade this computer? I do not have a PCI-Express or AGP slot. ONLY PCI is available. Is it feasible? Recommendations?

Since gravity is permanent, constant and unlimited, will all the stuff in the universe ultimately be all attracted together in some very dense singular mass? Granted, it will take a REALLY LONG, LONG time but it seems like everything will eventually suck together into one big pile of stuff. And what happens then? Thoughts?

I've got an old tv tuner that I'm planning to use and the connections on the back are: +B, Audio, Video and "E". Audio and video are obvious, I think "E" is earth or, ground. Is "+B" the DC voltage?

My old Dell is dying I think. Has worked for almost 7 years and it's time for it to go. I don't want Vista. I have heard to many negative things about it even to this day (May 2009). We use mostly Macs so I don't need the latest, greatest Wintel machine. Can I still order a machine with XP on it? XP works great for us.

This is for a guitar BTW. I know what a Bbm7 is but the (4) confuses me. What does that mean exactly....add a 4th? Why wouldn't that be written "+4". Do the parentheses mean something different? Thanks!

The blood of the horseshoe crab is very valuable to the biomedical industry. The crab are caught, some blood taken, and released. Much like we donate blood. Our question, how much blood is in a crab and thus how much is extracted during one "donation"? Thanks!

I am looking for information about restrictions on people in terms of where they live and work. Are there lawsuits and case law regarding residency issues as they relate to work. It seems ludicrous to me that it is legal to essentially control where someone can live/work. Labors lawyers out there.....thoughts?

This is a question from my children, one of which is studying simple machines in 5th grade. Could you lift an aircraft carrier with the mechanical advantage of one million pulleys. We'll assume for this problem that it is a frictionless system and that you could actually pull the rope thru a million wheels.

My initial feeling is, yes, you could. Of course, you would have to pull miles of rope I think but could it work? I don't know. What do you think?

Electric guitar pickups have many winds of thin copper wire to form an magnetic field in which the strings vibrate and produce electricity and eventually...sound. What would happen if you wound the pickups with silver or gold which, I think, have better conductivity than copper? Would it change the signal and/or tone? It would change the price of course to something prohibitively high and thus totally impractical. This is a "proof of concept" sort of theoretical question. You electrical engineers out there, what do you think?

I realize these impressive structures are to cool water. Presumably to cool water that is circulating through the whole system as steam, water, steam, etc. that is making the turbines spin and thus the generators. What I don't understand is why cool it at all? Isn't it headed directly back into the boilers to become steam again? Why not keep it hot and thus you need to use less energy to heat it. This is, of course, a simplistic uninformed notion I am sure. They wouldn't build those towers without a good reason. I'm guessing it has something to do with "state change". Can someone lay it out in layman's terms??

I've got an old Fender Super Reverb. I bought it 22 years ago and it was used when I bought it. I'm guessing it was made in the late 70's. It has been used sporadically through the years. It has never been serviced or re-tubed. It is currently being used again by a neighbor kid who needed a favor of a practice amp. It doesn't sound very good anymore. How much would a full service cost? It needs new tubes I'm sure but does it need new capacitors? New pots? Could I do this all myself? I have an excellent soldering iron, meters, some electrical skill and am generally not afraid to open stuff up. That said, I've never worked on a guitar amp. Should I save this thing?

I am looking for a list of specifics. What can nosey people learn about you? Where you vote? Where you are licensed to drive? Work records? Government records? Health records? Some of this stuff is protected and some isn't. What can someone get on you?

If you are wondering, I'm not a criminal on the run. Just curious after a recent conversation about this with a friend.

Our main exterior door for our house is terrible. It leaks cold air all winter. I want to replace it. It is non-standard and so is the opening. The door is 34 1/2 x 78. The opening is 39 x 81 1/4. That's the absolute maximum for the opening....any bigger would require a major re-engineering of the entrance to the house. Basically, every door that I look at is 36 x80 with rough opening requirements larger than my opening. The existing door is fiberglass and is bowed in at top and bottom letting cold air in along top and bottom. Aside from having a custom wood door made or something like that, do you have any suggestions? I would really like to invest a minimum in this for now and we expect to potentially make some major changes down the road a few years. Where can I get custom/odd size steel or fiberglass doors? Can I make a 36x80 door fit in there some how? I've thought about flipping the door upside down...is that crazy? Thoughts anyone?

This was a question from my children and I'm not sure of the answer when I think about it. I know that if you spin a magnet in an magnetic field (or ferrous material work too?) that you'll produce electricity. Electricity is the flow of electrons. If I think of the large generators that spin at a power company that are making large amounts of electricity, I realize that they are creating gazillions of electrons every second and sending them down the wire. Where, exactly, are these electrons coming from? When I think that electrons have mass (albeit very, very little), then I really wonder.....shouldn't something be losing that mass? Could a physicist put this in layman's terms for me?

Using a sealed lead acid battery (6V, 8 AH) I built a small power system for my camcorder (Canon XL1). I was tired of the of the small click-in batteries which were short lived and expensive. The SLA batt. is bigger and heavier but cheap and easily replaced and about twice the power. The problem is, the camera wants to see a slightly higher voltage than the battery is putting out (about 6.5V). The camera wants 7V - 7.5V. I didn't think it would be a problem but the camera blinks low batt the whole time and will occasionally shut down. I'm so close. I just need to raise the voltage about a volt. You electronic whizzes out there, is there some clever way to do this? Could I switch to 12v batt. and reduce it to 7-8 volts?

Perhaps the people here can settle a disagreement. My wife doesn't groom "down there" at all. With some peeking pubes noticeably protruding out in even a fairly conservative bathing suit, I gently suggested a bikini wax might be in order. She was put off by this and responded that not a lot of women do that. I countered and said that, although I have no real data, that almost all women perform some sort of maintenance there - from shaving to full brazilian. I wagered that about 90% probably do. I'm looking to back it up with some responses here or even better - a link to real polls. Thought ladies? Am I off base here?

I picked up some M-Audio Studiophile BX5 speakers at a garage sale and I would like to hook them to my computer. I have a fairly typical sound card with the mini jack output. The speakers are powered but have more of a pro audio interface. If you seen these, you know what I talking about. I need to get the proper cables for them. Frankly, I'm afraid to fry them as the last guy did (that's why I got them cheap - I had them repaired). On the back they've got the three-pin "Canon" style male connectors (like a microphone). Any thoughts? Thanks!

Can a union legally make rules that restrict the relationship of where you live and work? If you wanted to live, for example, in one area or state, but work in another periodically, but the union restricts that sort of migration, is that legal? Would that union "law" conflict with federal or state laws? Assume that we are not dealing with right-to-work states. For example, I live in Nevada and want to work in New York for a few weeks. Thoughts anyone on the labor law for this?