tvp45

So, what keeps the barge from slamming into the bank?

There are really two effects that account for this. One is that atoms are quite a bit smaller than the wavelength of visible light and so you can't "see" them with your eye. But, the other is what your brain does with light that enters the eye; look at a Monet painting, both closely and at a comfortable viewing distance. The individual cells in your retina respond to specific colors, edges, orientations, etc but your visual cortex organizes all that into something that makes sense.

Why did you use cos(25 degrees)?

You might look at Packmeister.com I have no experience with this but it looks like what you want.

Why do you think medicine is the slowest field? In the past, say 30 years, we've seen MRIs, CAT scans, PET scans, Gamma knives, brain plasticity, organ transplants, joint replacements, blood pressure drugs, cancer treatments, etc become commonplace. Hospital beds have almost disappeared as most surgery has become relatively straightforward. The part of medicine that has lagged is delivery and cost. We actually know how to largely prevent the common cold (handwashing, healthy humidity, staying home when ill, adequate rest, good diet, not sneezing or coughing on others) but don't.

SolidWorks would do this well in sheet metal mode, but that seems a lot of power and $ for what you want.

Reports like this are often "teasers" to attract additional funding, i.e., this certainly looks promising if only we could get another $20 million. If you read the report, you'll see they did a pooled analysis and did raise concerns about sample size.

Have you looked at electrostatic precipitators for HVAC?

And, there is an exception. The coefficient of kinetic friction for aluminum on dry aluminum is greater than the coefficient of static friction. (Avallone and Baumeister)

Sorry, I don't understand. What do you mean by regulator?

My experience has been that the design and manufacturing requires degrees and the power plants don't. Is that consistent with what you've seen?

I too have not read the link, but it is absolutely possible, in general, to use p only, pd only, or pi only (though God help you with instability on this one). Modified proportional is simple and often used, for example, in box heaters for electronic instruments where a few degrees of steady state error is no big deal compared to the cost of a real pid controller. A couple years ago, I built a two axis surgery table using hydraulic servos. Although I used pid, I put an off switch on the i so that, during the painstaking part of the surgery, the table would absolutely stay still wherever it was. So, yes.

Most car radiators are black because that is the cheapest, most widely accepted, color of corrosion protection. Car radiators are not actually radiators but rather convectors (or, properly, heat exchangers) and work by having hot liquid flow from the engine into the tubes where the heat is conducted to fins, past which cooling air is forced either by a fan or movement of the car. Corrosion inhibits that process. The cooling fluid normally contains corrosion inhibitors to control corrosion inside the tubes. The outside of the tubes actually doesn't matter much - it's the outside of the fins you want to protect - but as long as you're coating the fins, the tubes are free, and the outside is coated with a corrosion protection like, for example, anodizing. Many people think the black color has something to do with emissivity. It does not. The confusion arises from the fact that perfect emissivity is known as "Black Body Radiation". In fact, there are polished aluminum radiators, quite shiny, that work perfectly well. If you were willing to pay for it, you could even have an electric green radiator. Mr. Mongoose is probably right in thinking your teacher is a hand waver. I'd bet the answer he is looking for is that black radiates better.

Amen. I normally work in American units and routinely use slugs as a mass unit because it works, i.e., lets me use the same equations as the rest of the world. I don't think it's proper and it drives everybody else crazy. Then, there's the Troy or Avoirdupois question. Can we please change? Soon?

When I answered the OP, I was responding to the question "Why...". I hold that force is an operational definition rather than a foundational concept and, thus, completely outside any question of why. One might as well ask "Why are there sevens?" My answer would be, you can do arithmetic without them just fine. It'll be a pain in the neck doing the US currency or the SI units, but one could do it. I understand that many (most?) problems are easier when using forces. But problems and concepts are very different. Think about how many people think Faraday's Law says that a changing magnetic field induces current. That is conceptually deficient, yet some of the most sophisticated electromagnetic motors in the world are built by people who use that idea. Go figure.

If all your work will be in mass rather than volume, make a home-made balance beam (popsickle stick, 3 holes, 3 strings, 2 bottom ends of coffee filters). Use the paperclip calibration mentioned earlier. If you are doing only mass, actual units don't matter, only the proportions, so a paperclip accuracy is quite good enough.

It's like reading Penrose with a bad hangover and the wrong pair of glasses.

Check out Eric Rogers, a great presenter at Princeton some years ago. I think any demo might take a lot of equipment and time.

I'm probably more cynical than you. The press doesn't fall for it; they love it and encourage it because it sells papers and requires almost no reporting work.

It's either 2 or 53. If it's 2, Noam Chomsky will haunt you; if it's 53, Alexander Hamilton will.

If you really want to go there, consider a fall-back plan. At one time, Tech had articulation agreements with the Virginia Community College System. So, assuming some sort of agreement still exists (and it should), if Tech doesn't accept you, you could go to a VCCS two year program and transfer to Tech as (probably) a second semester sophomore or maybe as a junior.

The amount of force required is 2000.00000001 pounds (you can make the decimal part as large or small as you want - it only has to do with how much time you want to spend doing the lifting). The amount of work (which in this instance is equal to the increase in potential energy) depends on how far you lift it and can be as low as about 1000 ft-lb (remember that you must lift a real car about 6 inches in order to get everything up). Kinetic energy can be vanishingly small if you lift slowly.

But not in Lake Wobegone.

I think all metals can burn. I've seen sodium, aluminum, magnesium, iron, nickel, manganese, copper, lead, and probably something else that I can't remember. If you handle most metals, don't put your hands in your mouth or rub your eyes. Wash your hands afterwards.

"Why is there gravity?" That's easy. Tell your teacher it's there so water balloons will work.