Their cars run on DC motors (or at least get power from a DC source). Yet the company is named after a man who is acknowledged as the father of the alternating current (at least in the US).
Only the batteries are DC. The motor is AC and driven by an inverter in the car's Power Electronics Module.
As an interesting experiment. If you have WiFi and a microwave oven in your house/apartment, start downloading a large file. Look at the download rate (300kB/sec. or whatever). Then, start the microwave and look at the download rate. Mine drops to about 10-20kB/sec., because the microwave interferes with the WiFi signal.
Here is another one. Put your cell phone in the microwave, and close the door. DON'T TURN THE MICROWAVE ON. After a few seconds, your cell phone should say, "no signal," or "out of network," etc. If your cell phone still has signal after 10 seconds, it's time to get a new microwave. The housing of your microwave is no longer acting as an effective faraday cage, and is leaking dangerous amounts of radiation.
Natural Gas is mostly Methane. Since methane has the smallest ratio of carbon to hydrogen at 2 carbons, per 6 hydrogens, it is the best hydrocarbon to burn if you are trying to reduce carbon emissions.
Yeah, other sources produce no carbon, but they can't compete with Natural Gas's price.
Playing around with flow simulations and seeing how changes in geometry affect flow is fun
Agreed, but I'm afraid that playing with CFD will just leave the students frustrated and convinced that physics doesn't work because they can't get CFD to work. I remember kids in high school, (even some in college) deciding that physics doesn't work because they couldn't get newton's laws of motion to match the results they observed experimentally. In reality, they didn't do their math correctly.
If the author want's to quickly demonstrate the principles of fluid mechanics to his/her students here is my plan:
1) Make sure they have a firm grasp on Newton's laws of motion.
2) Have them drop a paperclip and a coffee filter from the same height and measure how long it takes them to hit the floor.
3) Explain to them that this is the effect of aerodynamic drag.
I performed the same experiment in college physics. It's quick and effective.
I agree that CFD would be something nice to teach a high school student. However, unless this is an AP course, CFD is just too complex for high school students. Most people don't learn CFD until grad school.
There are a few distributors who won't sell us movies that have some bogus exclusivity, but you know who will? Best Buy.
That is completely illegal. Copies of movies from Best Buy come with a different license than the copies purchased for rental. Therefore the rental copies cost more.
They are planning the first night flight to be close to the summer solstice. I suspect they will conduct their initial testing during while the day's are longer, and continue testing as they get shorter.
If they can fly all night north of 22 degrees latitude, and past the fall equinox, I will be extremely impressed.
According to the mathematics of general relativity, the event horizon should disappear if a black hole were fed enough charge and angular momentum relative to its mass.
Who's gonna go spin the black hole and zap it with a few billion tazers?
According to TFA, the researchers used theoretical juries of undergrads, and merely swapped the photo associated with them.
No, it doesn't say that. It says,
They were then given case studies of defendants, complete with a photograph and profile, were read jury instructions and listened to the cases' closing arguments.
It never says if the photograph was real or fictitious. However, using the same case study with different pictures would point strongly toward this being a cause and not just a correlation.
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the first person to get bingo, will be terminated.
That is all...
Reminds me of the time a garbage truck ran over a soccer ball in my old neighborhood. One of the hexagons was fused to the street for 10 years.
What advantage do AC motors have over DC ones? Isn't there a power loss because of the inversion?
In a DC drive system, torque is proportional to current, and speed is proportional to voltage. AC drives don't have that relationship.
Think of the inverter like a transmission in a car.
Their cars run on DC motors (or at least get power from a DC source). Yet the company is named after a man who is acknowledged as the father of the alternating current (at least in the US).
Only the batteries are DC. The motor is AC and driven by an inverter in the car's Power Electronics Module.
As an interesting experiment. If you have WiFi and a microwave oven in your house/apartment, start downloading a large file. Look at the download rate (300kB/sec. or whatever). Then, start the microwave and look at the download rate. Mine drops to about 10-20kB/sec., because the microwave interferes with the WiFi signal.
Here is another one. Put your cell phone in the microwave, and close the door. DON'T TURN THE MICROWAVE ON. After a few seconds, your cell phone should say, "no signal," or "out of network," etc. If your cell phone still has signal after 10 seconds, it's time to get a new microwave. The housing of your microwave is no longer acting as an effective faraday cage, and is leaking dangerous amounts of radiation.
my bad...
That's an even better carbon to hydrogen ratio though...
my bad...
Seriously, where did they get this claim: "The US said it is sure that most criminals use ICQ"
They probably got ICQ and IRC confused.
Natural Gas is mostly Methane. Since methane has the smallest ratio of carbon to hydrogen at 2 carbons, per 6 hydrogens, it is the best hydrocarbon to burn if you are trying to reduce carbon emissions.
Yeah, other sources produce no carbon, but they can't compete with Natural Gas's price.
The problem with this is that since it has happened once, it *is* going to happen again in a slightly different way.
If you RTFA you will see that the author believes it has happened twice before, just not as severe.
It basically sounds like the author is attributing the "Flash Crash" to lag from an insufficient quoting computer.
Playing around with flow simulations and seeing how changes in geometry affect flow is fun
Agreed, but I'm afraid that playing with CFD will just leave the students frustrated and convinced that physics doesn't work because they can't get CFD to work. I remember kids in high school, (even some in college) deciding that physics doesn't work because they couldn't get newton's laws of motion to match the results they observed experimentally. In reality, they didn't do their math correctly.
If the author want's to quickly demonstrate the principles of fluid mechanics to his/her students here is my plan:
1) Make sure they have a firm grasp on Newton's laws of motion.
2) Have them drop a paperclip and a coffee filter from the same height and measure how long it takes them to hit the floor.
3) Explain to them that this is the effect of aerodynamic drag.
I performed the same experiment in college physics. It's quick and effective.
But I figured a USGS link was in order.
Check out openFOAM [openfoam.com]. You might find that it meets your needs
Good answer. The price is certainly right.
The most widely used CFD software is probably StarCD. Unfortunately, it's probably cost prohibitive for a high school.
I agree that CFD would be something nice to teach a high school student. However, unless this is an AP course, CFD is just too complex for high school students. Most people don't learn CFD until grad school.
And they probably think that Jesse James was an outlaw from the 1800's.
No, Jesse James used to build stuff. We know who he is.
Who was that woman he was married to?
There are a few distributors who won't sell us movies that have some bogus exclusivity, but you know who will? Best Buy.
That is completely illegal. Copies of movies from Best Buy come with a different license than the copies purchased for rental. Therefore the rental copies cost more.
I put in a request for a machine 6 months ago and still haven't received it.
They are planning the first night flight to be close to the summer solstice. I suspect they will conduct their initial testing during while the day's are longer, and continue testing as they get shorter.
If they can fly all night north of 22 degrees latitude, and past the fall equinox, I will be extremely impressed.
According to the mathematics of general relativity, the event horizon should disappear if a black hole were fed enough charge and angular momentum relative to its mass.
Who's gonna go spin the black hole and zap it with a few billion tazers?
Anybody?
Come on, it's for science!
in the summer the difference between warm sidewalks and the inside of the boot will not generate any electricity.
You haven't met my wife. Her feet are ice cold in any weather.
I've been telling her I'm going to use her feet as a sink for a heat engine. It looks like today is the day!
I find it exceptionally ironic that Chicago is one of the places this is illegal, because the city is blanketed with police surveillance cameras.
Linux is hard to use?
According to TFA, the researchers used theoretical juries of undergrads, and merely swapped the photo associated with them.
No, it doesn't say that. It says,
It never says if the photograph was real or fictitious. However, using the same case study with different pictures would point strongly toward this being a cause and not just a correlation.
The picture of the plane raises all kinds of questions? What are the wings made of? Where do they store the fuel?