Recent content by plusaf

you might also try http://www.howstuffworks.com/ or http://howthingswork.virginia.edu/ for explanations of how transmitters and receivers encode and decode information over electromagnetic (or other) media. +af

tony, it might be worse than you think...:smile: if there more and more stupid students entering college, compared to the nunber of smart ones, the "ratio of stupid to smart students" will be getting bigger, not smaller. as for the guy who asks questions like the log2 of 3 question, well...

i agree completely. a professor who beats everyone into the ground has a psychological problem which should be brought to the attention of the Dean of Students. they're there to impart knowledge, and the tests are the measurements of the success of their efforts. in theory, the fact that...

yeah, and if you continue that all of your life you'll end up depressed or suicidal, and you don't deserve that. you're NOT responsible for everything that happens, and neither are they. share the blame and share the responsibility. a good teacher, even in high school, CAN be extremely...

yeah, "pep talk"... right... if you've made it to your junior year, you've gotten past the "i didn't learn how to study" part of college which flunked me out at the end of my sophomore year. the distribution you describe is strange, in itself. if the testing material really reflected the...

From Similarly, if the spacecraft files at Mach 20 "on earth" (over the earth), how many m/s or km/h is its ground speed? if it flies at that ground speed on the planet with the H2 atmosphere, what's its Mach speed? not so hard when you say it that way? again, +af

From if you know the radius of the shuttle's orbit and the time it takes to complete an orbit, you can calculate its orbital speed. that's simple math. if you assume that upon re-entry that speed doesn't change, and at whatever altitude it "re-enters" the atmosphere, the speed of sound...

---- in physics and chemistry. many of the web references or wikipedia entries or google results will include "potentiometers" which are used as voltage dividers, as in any and all analog volume controls in audio equipment. in those situations, current does flow and resistance/impedance of...

great job, bystander! let me add this for the benefit of the non-electrical engineer who asked the original question: picture a meter-stick with a thin wire stretched along the length of it, over the numerical markings, 1-100cm. a power supply is connected to the wire: one end to...

um, I'm a little confused. you know the coeffecient for the spring, which says that if you pull on it with a force of 55N, it will stretch 1m. you hang a 1.9kg mass on the end of the spring. it stretches to a new length. can you figure out how many N of force the 1.9kg mass exerts on...

not a dumb question at all! but the other answers might make your head hurt... try this: electrical potential energy, especially easy to see in the model of a parallel-plate capacitor, means there are more electrons on one plate than the other. very simple. the more the difference in...

i'd start with assumptions: 1) no air resistance 2) gravity is that of Earth 3) can you write an equation that describes the motion of the projectile that can be solved for the unknown you're looking for? um... and the first one is worded poorly. "missiles" are usually "fired" or...

please let me add this: the equation given in the beginning tells what the current flow for "the circuit" will be versus time. the problem statement invites your mind to try to figure out what kind of circuit could produce that kind of charge flow. :) that's irrelevant. the equation...

just a shot in the dark... it's late here... start with an assumption of a unity driving signal... one volt rms and one Hz. i'd bet that in the end the frequency and voltage drop out of the final solution.

excellent, and beautiful, too!