Engineering - May 2007

I want to understand active filters and why op-amps make them function so well.

I gave up on trying to derive a transfer function for a four pole butterworth filter. Can you describe how it works or link to a website that derives a transfer function for an active filter? Thanks

2007-05-05 10:56:37 · 5 answers · asked by Matt 2

I have a 1 1/2 inch pipe making 7.6 gpm, Im trying to figure out what the PSI is to see how much volume I will loose if I increase pressure with say a 3/4 line

2007-05-05 10:21:24 · 8 answers · asked by fubadmonkey 1

In skool we have 2 make a 2 liter bottle rocket, with just using water to launch it up in the air! I am just wonderin' if any1 knows a good way to let it stay up in the air longer and shoot up in the air really high! If ur idea is good i'll give u best answer! thanks 4 ur help!:)

2007-05-05 07:58:45 · 1 answers · asked by pinay4lyfe 3

2007-05-05 07:56:28 · 1 answers · asked by Afshin 1

2007-05-05 07:20:58 · 11 answers · asked by Raymondo 1

A&P Technican

2007-05-05 06:36:52 · 2 answers · asked by Anonymous

what do you mean when you say xr2206 is used for sweep generation and its sweep range is 2000:1

2007-05-05 06:27:27 · 3 answers · asked by Anonymous

My guest house has been burglarized twice this past week. The electrical wires are antique and need to be replaced, so there is no electricity in the house now and I'm not able to have it rewired yet. We've secured it with locks, but they're just cut, picked or jimmied. The house is barely visible from the street and backs up to an alley, so the criminals have plenty of privacy and I can't change that since it's not blocked by shrubs.

Video tape of a crime is not accepted by police here and we're not allowed to use barbed wire on the fence, or electrify it. I do have a doberman, but she accepts treats from strangers. When she saw the guest house door open, she ran in and came out with a stuffed animal to shred.

So, I am considering booby-trapping the house....like the kid in "Home Alone". Can someone give me some clever ideas about things I could do?

2007-05-05 05:06:16 · 6 answers · asked by swissmiss620 4

2007-05-05 04:16:40 · 9 answers · asked by Anonymous

* When on plane/flat road or sloping down I put the lever on neutral, as the car will keep going at the same speed or faster (coasting) without using petrol.
* I use that also when expecting to stop for a traffic light, few 100 metres ahead.
* I believe it also to relieve the motor by choosing neutral when stopping at traffic lights, instead of keeping the foot on the brake pedal.

2007-05-05 02:20:04 · 4 answers · asked by Anonymous

Just one of my hairbrain ideas. I once saw a episode on HorsePowerTV about making Bio Diesel in your own garage. They said that you could make your own fuel for around 70 cents a gallon. Would this make it even remotely possible to generate electricity with a diesel generator at a cost comparable or possibly cheaper than what most utility companys charge. I'm sure the answer is no, but I thought it would be interesting to find out what someone with some knowledge might have to say.

2007-05-05 02:16:49 · 3 answers · asked by Anonymous

I just bought this LEDs http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=012&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=220105849747&rd=1&rd=1

i want to make a flashlight with a 100 of this LEDs

The criteria or this project is :
- Using 100 LEDs
- operated in 6v or 9v
- using D cell batteries

Please your proffesional advice about how should i get this project done, my question is :
- should i use Parralel or Series connection for the led, or maybe any good combination?
- What kind of resistor i need to add (if any)
- If posibble i will like to use transistor and any other circuit rather than just resistor to supply the right voltage.

I have an advice to use 9V D cell Batteries and connect the LEDs with "50sets of 2 on series in parallel" and use resistor to fit the voltage needed.

I hope i can have more choice for doing this project

Thanks

2007-05-05 00:31:19 · 4 answers · asked by senjaya_chang 1

2007-05-04 21:14:36 · 4 answers · asked by Anonymous

whats the problem

2007-05-04 21:02:00 · 5 answers · asked by CHRIS H 1

2007-05-04 20:59:55 · 9 answers · asked by peterphillips.php@btinternet.com 1

Conspiracy fanatics claim that the proof that the World Trade Center Building 7 was imploded is that if fell too fast (usually stated at 16-17 seconds) even though it had a 10 story gash into the building and stood for most of the day. Obviously these people think they know how fast a 47 story building "should" fall. Is there any video record of any other 45-50 story building going down "slowly"?

2007-05-04 20:48:23 · 2 answers · asked by Mike1942f 7

i am working in a petrol station where there is 4 wire armour cables entering a junction box each supplying 4 lighting circuits
3 have 240v supply one has 110v in which the lights are not working they may be through a contactor im not sure yet im trying to resolve this problem could you help me please
chris.hanlon36@btinternet.com

2007-05-04 20:44:56 · 4 answers · asked by CHRIS H 1

I'm studying about a sintering plant. It is the only sinter plant in the world that is detached from a steel mill complex. Why is this so? Is sintered iron ore a raw material to make steel bars used for building bridges, buildings and others? After iron ore is sintered, what does it actually look like? Is iron ore also called limestone?

2007-05-04 20:16:51 · 2 answers · asked by di 1

I start with a piece of 300 series stainless steel that measures 1foot (12.000 inches) in outside diameter with 3in. (3.000 inch) hole in center. The starting temperature of the steel is 120 degrees fahrenheit.

When the piece of stainless steel cools to 70 deg fahrenheit what is outside diameter measurement which was previously recorded at 12 inches? What is the new inside diameter?

What is the coefficient of expansion formula for this observation? And notice that the temperature is measured in fahrenheit.

You must show your work.

2007-05-04 19:59:31 · 1 answers · asked by rockyes1 1

anybody know where to find it??? the questions are too hard to be solved~~~

2007-05-04 18:56:45 · 2 answers · asked by never_cry_for_nothing 2

2007-05-04 18:06:57 · 8 answers · asked by Anonymous

It sounds like "kinescope" which has a lengthy article on wikipedia, but it might be something completely different. Anyone know for sure?

2007-05-04 18:04:54 · 3 answers · asked by billyboy 3

please give me some channel to make realize my question

2007-05-04 16:05:16 · 1 answers · asked by Okky_elektro 1

I really don't know why they name it "constant volume". In a reciprocating engine, the piston moves up and down. The volume of the air always changes, so how do they call it "constant"?

2007-05-04 13:59:31 · 4 answers · asked by tasd 3

useful convertion table for example: Pressure. Temprature, flow,time,....

2007-05-04 13:53:42 · 5 answers · asked by d. b. 1

Explain the pro's and con's of each please if you would. This is for a diversity paper and just trying to get some info on them.

2007-05-04 13:22:15 · 7 answers · asked by Anonymous

I did this calculation for a 12 gram CO2 cartridge and i know its not really the pressure inside of the CO2 it much to low, heres my question. I need to find the pressure inside a 12gram CO2 cartridge, i know the mass, n, t, and r, however i do not know V. What i did was use the mass and density to find V but density i used i believe is for STP which this is not. The 12 gram has CO2 gass inside no liquid does anyone know what the pressure inside the 12 gram is or which denisty to us to find it?

2007-05-04 11:05:08 · 4 answers · asked by domnator16 1

I am doing a project where i need about 100 of the small christmas lights. I need to be able to light them on command. I also need them to plug into a 120 v wall outlet. My problem is, when i light just one or two of the lights, they blow. How can i reduce the voltage going to them so that they will not blow, yet raise the voltage when i need to light a larger number of the lights? Thank you for your help.

2007-05-04 11:00:49 · 5 answers · asked by platinumpimpin6969 1

1 ton of material will cover 1.09 cubic yards at 1" depth.

2007-05-04 09:48:38 · 5 answers · asked by Brett V 1

2007-05-04 09:02:28 · 4 answers · asked by Kiesha J 1