Engineering - March 2007

why is it that you cannot throw a raw egg against a wall without breaking it, but you can throw it with the same speed on a sagging sheet without breaking it?

2007-03-11 14:07:10 · 8 answers · asked by shelin_113 1

Will a very moist environment and almost-damp materials change the acoustic performance of a space?

If the material is sufficiently waterlogged, I can see it changing the absorbtive qualities of a material. However, I'm not sure if water damaged materials that have been dried will have any changes in their acoustical performance. Any ideas?

2007-03-11 13:55:22 · 1 answers · asked by peachfuzz 3

2007-03-11 12:54:47 · 2 answers · asked by Anonymous

Where to buy a DC-to-DC converter, input 12VDC nominal, output 120VDC nominal (actual 145-155V)?

Hi, I would like to run high-amperate 145-155Vdc devices [nominal voltage] from forty 12Vdc automotive batteries in parallel. Is there a product that does this. The output should be regulated, too.

If this product doesn't exist, how easy would it be to make one?

P.S. A "12V" battery puts out 12.9 volts at 100% state of charge and 12.2 volts at 20% state of charge.

2007-03-11 12:31:25 · 4 answers · asked by Dr. Quixote 1

why does copper conduct electricity but rubber doesn't. Not only this, but the answer needs to relate to the particle theory.

2007-03-11 12:23:58 · 5 answers · asked by aditya_dhaliwal 1

2007-03-11 11:13:04 · 4 answers · asked by currentcover 1

2007-03-11 10:52:34 · 3 answers · asked by Anonymous

I want to know everything about grout used in repairing cracked structure, types of grout, the method of repairing cracks, the material that usually used as the grout matrix, the effect of using sea sand as the grout material, the effect of chloride content of sea sand towards structure in short and long term, and how to remove the chloride content in sea sand and made it available to be used in construction. This information will be very useful for my study.

2007-03-11 09:52:17 · 2 answers · asked by zizou 1

2007-03-11 09:37:50 · 1 answers · asked by Anonymous

I need to support a shaft that will be the axis of a centrifuge. The shaft will spin round at about 1000 rpm. It will be loaded axially by 1 ton, which will have to come through bearings. The centrifuge will be out of balance. The rotating out of balance load will be equivelent to a radial force of 5 tons. What type and size of bearing do I need?

2007-03-11 09:31:28 · 4 answers · asked by Always Hopeful 6

just wondering

2007-03-11 08:54:26 · 5 answers · asked by macgyver 1

2007-03-11 08:45:42 · 4 answers · asked by coolerthanu 1

what are the advantages & Disadvantages of the FRONT LOADING washing machines when we compare it with the TOP LOADING washing machines. Though, we have fully-automatic on both the models and why the front loading machines cost more than top loading machines.

2007-03-11 08:39:59 · 2 answers · asked by Mohan 1

i have a dc permanant magnet electric motor and want to use a gearbox to vary the speed of an electric vehicle.The vehicle weights about 200kg and have a maximum speed of 2m/s.

i just have only one choice of varying the speed(so i cant use a electronic controller), a step down gearbox which is:

http://www.thegreenreaper.co.uk/ShowDetails.asp?id=564

I am not sure why,but this gearbox have a maximum speed of 2000rpm for the motor input. The maximum gear ratio is 68:1 and the lowest is 17:1.

i know that to calculated the output speed is equal to:

rpm = speed/ 2*phi*r

since there is a limit on the input speed,the thing that i am confius about is:

How do you calculated the maximum speed that the motor could achieved(in this case is 2m/s), when the maximum input speed for the gearbox is 2000rpm(which is basically at the NO LOAD speed of a motor)....

2007-03-11 08:39:23 · 1 answers · asked by eddy1234 1

I have owned a Fluke handheld DMM for several years now, and have never had it calibrated. Is this something I can do myself? What kind of equipment/standards are required? Or do I need to send the meter to some lab to get calibrated? I just use this for hobby electronics, so it isn't too important that the DMM be super accurate. I was just wondering what was involved with calibrating one of these.

2007-03-11 08:27:23 · 4 answers · asked by Jess 2

I want to design a plate of variable thickness and complex shape to withstand bending in two directions; what finite element analysis software do you recommend and why?
Please understand that I am old and need a really hand-holding type of help.
Any help or advice is appreciated.

2007-03-11 08:24:35 · 1 answers · asked by kellenraid 6

if u measere say 20 inchsquare from diagonal corner to diagonal corner shouldnt it measere 20 inhes there as well?

2007-03-11 08:02:17 · 3 answers · asked by Anonymous

heres the diesgn
http://img461.imageshack.us/img461/5324/save0301rp6.jpg

if theres is something wrong with is tell me what i need to inprove or fix

2007-03-11 07:59:41 · 4 answers · asked by macgyver 1

Looking for sponsorship / part time employment for son who is studying Elect/Mech Degree at university.

2007-03-11 07:58:52 · 1 answers · asked by laura123 1

if you look at it if the base is at the top, is the emitter on the left or the right of the transistor

2007-03-11 07:53:28 · 5 answers · asked by macgyver 1

It is a three wheeler. One wheel front two back. Check out the pictures they might help: http://flickr.com/search/?q=Carver+one
Just wanna know how can it tilts. The company mentions a hydraulic system. But I want to understand how does it work. Please help. Maybe this can be of assistance: back doesn't tilt( 2 wheels), only front does (1 wheel and cabin).

2007-03-11 07:48:30 · 1 answers · asked by Youngboss 3

how to made acoustic board ? and what material did they use?

2007-03-11 07:32:24 · 0 answers · asked by tyn_christine 1

this process used to join metal tubes and fitting toghether in aircraft industry

2007-03-11 07:26:09 · 1 answers · asked by jet boy 1

does the variable capacitor (is the tuner) need to be at a higher capacitance so it recieces higher frequencies

2007-03-11 06:47:01 · 1 answers · asked by macgyver 1

smart parking lot project, shopping robot

2007-03-11 06:40:36 · 5 answers · asked by lattevo 1

I have a propane can which I use to fill up my airsoft gun with gas. Would it be possible to refill a Turboflame Phoenix lighter/blowtorch with the same can?

The manual says you can use Butane gas, I'm just wondering if propane would work too and if I'd need a special adaptor.

Thanks!!

2007-03-11 06:37:37 · 2 answers · asked by Will G 1

2007-03-11 06:02:13 · 1 answers · asked by mail_vikasgautam 1

Can Infrared used to measure distance?This is because commonly found in the market is ultrasonic measurer with laser pointing to measure distance.Any suggestion?Or somebody with this infrared measurer project?

2007-03-11 05:47:48 · 2 answers · asked by imranhakim03 1

2007-03-11 05:41:50 · 3 answers · asked by sul m 1

it should be digital to feed back to the electro motors to order them.

2007-03-11 05:34:42 · 1 answers · asked by Anonymous