Search results

  1. V

    Imperial measurements just feel better

    Metric holds an advantage in simplicity, but imperial seems to have better unit amounts. For instance, temperature. I cannot think in celcius. 60's weather is 15-20 celcius. 70's is 20-26 celcius. 80's weather is 27-34 celcius. Lengths: a mile is a significant accomplishment for human...
  2. V

    George Russ, rogue oceanologist, dumped 100 tons of Iron Sulfate into the ocean Last fall. His intention is the stimulate the growth of phytoplankton, thus absorbing CO2. He also did so in violation of several UN charters (or whatever their rules are...
  3. V

    How long does it take the Earth to form one gallon of oil?

    Like the title says. I"m guessing tens of thousands of years?
  4. V

    How much rocket fuel is burned in the first mile/kilometer?

    Take a typical single-stage rocket that reaches low earth orbit (that's around 2000 km). How much fuel is burnt just to get the thing a foot off the ground? Or a kilometer or a mile? 10%?
  5. V

    Could an ion engine attached to a satellite be used to stabilize orbit?

    Basically, my understanding is that every satellite that is not at a lagrange point will see its orbit eventually decay and it will crash back into the earth. Could an ion engine be set to fire at certain times to offset this? Because the rate of decay is slow, an ion engine might be up for it...
  6. V

    How much is the ideal rocket equation affected by air drag? ideal rocket equation. No fudge for atmospheric drag. how much is it a factor?
  7. V

    Maintaining orbit around the moon Basically, wouldn't any object that orbited around the moon gradually see its orbit be made more and more eliptical until it crashed into the moon itself? Also, it actually takes...
  8. V

    What is the unit to use in evolution?

    And what are some good examples besides humans? I'm guessing that years don't matter as much as generational cycles. edit: for example, how many evolutionary cycles for humans would be contained in 100 years? Or dogs? Do you count by total age or reproductive age?
  9. V

    Is it possible at all to go faster in an orbit around the earth?

    My understanding is that generally with space flight, when you accelerate in the direction of orbit, you don't go around the earth any faster but instead ascend to a higher orbital plane, which arguably has a longer period of orbit. Is there any manuver method that lets you move around the...
  10. V

    Centrifugal force for gravity in space stations: what other problems would result?

    Hi, Doing a quick scan of wikipedia, a radius of 22m going at 10 RPM would produce 1g in gravity on the edge. However, wouldn't other forces of the spin, torque and angular momentum, create huge problems? Intuitively, if I hold a spinning bicycle wheel, it is highly unstable and the...
  11. V

    News Pakistan is the problem

    I find it impossible to believe that Bin Laden was able to live for five years in the Pakistani West Point without any collusion with the government or military. He even traveled to and fro in that period, from Abbottobad to Tora Bora and back in 2007. The reason that pakistan does this I...
  12. V

    Kenneth miller thinks god exists in quantum mechanics

    I'm almost finished with his book finding darwin's god. In short, I feel like he skirts dangerously close to ID with this notion. Basically, Miller reconciles evolution with God by saying that, while this could be reductionist, it was God that created the conditions that led rise to...
  13. V

    Resistors in front of capacitors

    Most arrangements I've seen have a power source hooked up to a resistor hooked up to a capacitor. Like this Why? I mean, why can't we directly hook the capacitor to the emf? sounds stupid, I know. Also, resistors follow...
  14. V

    A Determinant's relation to permutations

    for a 3 x 3 matric of values a11 a12 a13 b21 b22 b23 c31 c32 c33 the determinant will be a11a22a33+a12a23a31+a13a21a32-a13a22a31-a12a21a33-a11a23a32 the last three are negative because they are odd permutations. The first three are even permutations A permutation apparently is...
  15. V

    Closing a Circuit

    24.89 Giancoli There are three capacitors. One is in parallel with two others. The two others are in series. The alone one is 2.8 uF, the other two in series are 4.4 and 3.7 uF. a 12 volt voltage is applied. Initially there is a bridge that connects to the 2.8. After it is charged, the switch...
  16. V

    Adiabatic Process

    I'm having a hell of a time understanding this. Can anyone give me a hand? How is it derived? etc?
  17. V

    Can a Moment propel?

    if I spinned a flat blade (eg: no lift) clockwise it should go up, and counterclockwise it should go down in accord with what I've been taught so far about the cross product as it relates to statics. Does this occur? Off hand this doesn't make sense. But the math seems to suggest it...
  18. V

    Kinetic Energy in relation to the ideal gas law

    I'm trying to fit this together. For monotomic molecules, the avg kinetic energy is 3/2 k_b T for diatomic, it is 5/2 k_b T PV = n_particles * k_b T Why is there no factor of 3/2 or 5/2 in the ideal gas law? How is it factored out?
  19. V

    How many molecules of monotonic and diatomic gas are in a container?

    1. You have a container of 3300 cm^3. Half of it is diatomic oxygen and half is monotonic helium. Pressure is 17 atm and temperature is 25 degrees C. How many molecules of each substance are in it? 2. PV = 2/3 N(1/2 mv^2) -> PV = 2/3 N (K) -> N = 1.5 PV/K K_monotonic = 3/2kT = 3/2...
  20. V

    Changing evaluation of an axis on a triple integral

    So I'm in the middle of a calculus 3 course, and one thing I've been lightly chewing on is how to change the direction of evaluation of a double/triple integral when the bounds are complicated enough that they can't be drawn easily on a graph. Would you have to use the optimization in several...
  21. V

    I'm on a second bachelors - how much will the first drag me down?

    I'm on a second bachelors -- how much will the first drag me down? I did very badly at my first shot at college. It took me 5 years to barely graduate with an english literature degree. I hated life in college, but I especially hated life after college. In that time I went up to Physics 2...
  22. V

    Hess's Law

    So in Hess's law, I have a question on the why. from an example in my book, c+h20-> co+h2 and the intermediary reactions are C+o2 ->Co2 2CO+O2->2Co2 2H2+O2->2h2O Along the way, the second reaction is reversed and halved. Now, Hess's law says that the pathway is irrelevant...
  23. V

    Temperature resulting from the formation of water

    Basically, I need confirmation on the heat produced when four mole of H2O is produced from Hydrogen and oxygen gas. I'm getting something ridiculous, basically saying that the temperature goes up to ~4000 degrees C. What I'm doing is using Hess's law to find the energies of reaction. H2 and...