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Sensei

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Everything posted by Sensei

  1. Ep = m*a*h Distances traveled by object with acceleration a is: h=1/2*a*t^2 so m * a * 1/2*a*t^2 = 1/2*m*a^2*t^2 kg * m^2/s^4 * s^2 = kg * m^2/s^2 = kg * (m/s)^2 And we are receiving other equation back. Ek= 1/2 *m * v^2
  2. Then your teacher is incompetent.. Because it's in flagrant conflict with this "(Hint: use pass by reference)"... In ANSI C, you have to replace references by pointers. #include <stdio.h> void getNumSum( float *aSum ) { float data = 0.0; printf("Please input a float number: "); scanf("%f", &data ); *aSum += data; } void main() { float aSum = 0.0; for( int i = 0; i < 5; i++ ) { getNumSum( &aSum ); printf( "Sum %f\n", aSum ); } }
  3. References are in cpp, not in old c. Rename file and should be fine.
  4. You named file .c but it's .cpp code
  5. It's not exactly what I posted in #4. Compare lines one by one..
  6. Can't you simply copy and paste to compiler what I wrote in post #4? This time I have compiled above code, and tested and worked as intended...
  7. Photon with initial frequency f0 should decay to two (or more) photons with frequencies f1 and f2, which are sum: f0 = f1 + f2 (energy must be conserved) So we actually see decay of photons in entire Universe all the time when photon is absorbed by matter and new photons are emitted at longer wavelengths.. Fluorescence is example of this process. High energy UV light is absorbed, lower energy visible light is emitted. But it's induced decay. By medium that's on photon path. But how can you be sure whether photon emitted by galaxy f.e. 10 bln light years from us wasn't absorbed and emitted by some material between galaxies.. ? Spontaneous decay the most likely won't be distinguishable from induced decay by interaction with medium..
  8. Rather something like this: #include <stdio.h> void getNumSum( float &aSum ) // do you see difference here?? Parameter must be with & { float data = 0.0; printf("Please input a float number: "); scanf("%f", &data ); aSum += data; } void main() { float aSum = 0.0; for( int i = 0; i < 5; i++ ) { getNumSum( aSum ); printf( "Sum %f\n", aSum ); } }
  9. void getNumSum( float &aSum ) { float data = 0.0; // ask user for float here... aSum += data; }
  10. What random numbers you are talking about?! If you'll measure your mass to be f.e. 78 kg it means that you are made of: mass of proton/neutron is approximately 1 g/Na= 1 g/6.022141*10^23 = 1.66 * 10^-24 g ... 1.67 * 10^-24 g (different element have different mass of protons and neutrons f.e. Carbon-12 has mass=12 g/Na, but Hydrogen has mass 1.0078 g/Na) 78 kg = 78000 g 78000 g / 1.67 * 10^-24 g = ~4.67 * 10^28 protons and neutrons approximately in 78 kg body.. How can we calculate mass of Hydrogen and Oxygen? While electrolysis.. We are filling box with well known mass and volume of water. Then start electrolysis. In one test tube there is collected Hydrogen and in other test tube is collected Oxygen. We can measure volume of Hydrogen, volume of Oxygen, mass and volume of rest of water in box.. Using Hydrogen and Oxygen as product to create other substances we can gain knowledge about molar masses of the all elements.. And you can do it in couple minutes at home.
  11. It's easier to see process with animals than vegetables. Imagine that we have bears that have childes. Parents can have whatever colors. Childes have: one white, one gray, one black (natural mutations). If they would be living in forest, white one would be easily visible by preys, and couldn't survive and spread its genes to the next generation. If they would be living in arctics, white one would be the hardest visible, unlike gray and black one, which wouldn't survive, starving. White one would spread genes. Species with wrong color in environment are not surviving. Predators can't be easily visible to preys. And preys can't be easily visible to predators. Pigeons owners are using this knowledge to create white only pigeons. Even if original parents have natural colors. But instead of predators they are choosing which color birds should survive. Vegetables more often fight against eating by animals by creating toxics substances. Or by making fruits good to eat, so other part of vegetables are leaved intact by animals.
  12. The simplest fusion is process of joining two protons together: p+ + p+ -> D+ + e+ + Ve In order it to happen, there is needed to overcome natural electrostatic repelling of two equal charges. Do you understand now why they have to be accelerated? Hot particle = fast particle. Cold particle = slow particle. This can be rewritten using quarks: uud + uud -> uud + udd + e+ + Ve At least one of up quarks must have enough kinetic energy, or receive from external source, to be converted to down quark which according to quark model has higher mass than up quark. Newly created neutron is joining with proton forming Deuterium. p+ + n0 -> D+ uud + udd -> ududud
  13. Try something like: for( j = 1; j <= x; j++ ) { for( i = x; i >= 1; i-- ) { if( i > j ) { // print star } else { // print i } } }
  14. Sensei

    Chemistry

    Which triprotic acids did you have at school?
  15. I posted it to inspire people to experiments. Everything should be created, checked and published. For dead rats and small animals these things are not negligible and worth ignoring. Replacing H by D, is just an example. H2O has 18u HDO has 19u (+5.5%) D2O has 20u (+11%) Some might say it's small change in mass.. (apparently not small for dead rats) CH4 has 16u CD4 has 20u (+25%) Is it still small and not worth experiments showing what properties will have Methane with Deuterium? C2H5OH has 46u C2D5OD has 52u (+13%) How other substances will behave after putting them to Deuterium Ethanol? Will they be soluble (or not) at the same as with normal Ethanol? etc. kind of questions can be asked. How will behave polyethylene/polypropylene which has only Deuterium? Will it bend or crack at the same moments as regular one? Without creating these substances and careful examination how they behave we can't judge with 100% certainty how they behave.
  16. Hello! Heavy water according to wikipedia is causing death of rats in a week of drinking. http://en.wikipedia.org/wiki/Heavy_water The only difference from water is replacement of Hydrogen element by Deuterium, D2O or HDO. Just because of extra neutrons properties such as boiling point, and melting point are slightly different (not to mention other hidden properties hard to measure). D2O (Heavy water) Freezing point (°C) 3.82 Boiling point (°C) 101.4 HDO (Semiheavy water) Freezing point (°C) 0.0 Boiling point (°C) 100.7 H2O (Light water) Freezing point (°C) 0.0 Boiling point (°C) 100.0 This example shows that it's important to examine the all chemical substances with careful counting their neutrons as standard procedure. Produce isotope pure element, then mix them with other isotope pure element, receiving mixture with well known neutron quantity, and use it instead in tests. Hydrogen chloride acid can have more than 6 versions (4 stable): H-Cl-35 H-Cl-37 D-Cl-35 D-Cl-37 T-Cl-35 T-Cl-37 Their properties should be slightly different. Also result of their reactions with other substances should be slightly different. Precise experiments should show how much. Taking proper care of neutrons should open door for finding old-new materials, with different parameters (starting from different boiling, melting points). f.e. plastics with Deuterium instead of Hydrogen in chains.
  17. Hello! Do you know some application for generating chemical formulas? I mean something like- enter quantities of atoms, and program should show the all *) existing and plausible chemical formulas possible to make from them. f.e. If I enter C=1,O=2, it will show CO2 (O=C=O), If I enter C=3,H=8,O=1, it will show CH3-HCOH-CH3 but also C3H7OH *) in reasonable amount..
  18. Beta decay- and beta decay+ of radioactive element is the most common way neutrinos are produced on Earth. http://en.wikipedia.org/wiki/Beta_decay Double decay is one of neutrino-less nuclear transmutations. http://en.wikipedia.org/wiki/Double_beta_decay
  19. Slit for us is smooth and thin, but after large zooming it's more like tunnel with mountains (this can be seen in any microscope). Photon traveling close to the edge of slit is colliding with one or more "mountains" and is reflected. Similar thing happens when you shine laser pointer on wall- regardless of angle at which you look at wall, you see laser dot. How? Photons colliding with microscopic impurities in the wall are reflected in the all directions. From one steady beam of photons, they're spread everywhere. Modern military airplanes and u-boats are using similar impurities on the body to be undetectable by radio and sound waves. They are reflecting waves in the all directions, instead of like smooth body sending them back to radar.
  20. Do you want to find out where your magnet has N and where has S? You can do it using compass. http://en.wikipedia.org/wiki/Compass If you don't have it, you can create it in a couple seconds. You will just need f.e. glass of water and needle (in minimum version). Move your magnet in straight direction on needle to magnetize it. After that other needles will start attaching to it. Then carefully place on water. If done properly it won't sink (if sink use magnet to take it from water and repeat). Some people attach something unsinkable to needle, but IMHO it's degrading speed in which needle will react. Now you can rotate your magnet in hand, and see how compass is also rotating synchronously. The stronger magnet you have, from longer distance you will be able to rotate or change direction of compass. You can make array of compasses and see magnetic field lines. Once I had 20+ such homemade compasses in whole apartment Funny thing, none pointed the right direction to Earth's N-S. Too many electronic equipment. The only unaffected place is here balcony. You can verify this at 12:00 looking at Sun, compass should be pointing one end to Sun, and 2nd end in Earth's north.
  21. Why not use laser cooling to freeze water? It can be direct, or indirect. In indirect method, use f.e. helium with well known wavelength of photons, take energy from helium, helium atoms will take energy from metal box where it's stored, and metal box will take energy from environment. In our case, water. Another idea is utilizing Mpemba effect http://en.wikipedia.org/wiki/Mpemba_effect
  22. If you will use 3rd party library, you will learn how to link against linkable (or dynamic) library, not compression/decompression algorithm. If you want to learn something useful, try making compression/decompression algorithm by yourself. If it's job ordered by somebody, and you will use 3rd party library, you might break license agreement they want to maintain. Some 3rd party library authors disallow selling software made with them (only share, or only share with open source depending on lib). That's mentioned in their license.
  23. People don't understand how Universe works because the way teachers learn it in primary and high school, going in chronological order of discoveries (at least here), which confuse a lot of people when they finish learning at this level and no go further to quantum physics. And here is example of this. What do you think is electricity? In closed system, number of electrons is CONSTANT. So the same number of atoms,protons,neutrons in conductors (in f.e. wires) and isolators. In electric generator no single new electron is created. Electrons existing in system are accelerated. Ek = e*U v=sqrt(2*e*U/me) e is 1.6*10^-19 C me is 9.11*10^-31 kg both constant so velocity of electron is pretty much v=sqrt(3.512624*10^11*U) (for no relativistic speeds) When accelerated electrons are colliding with atoms in wire, they're decelerated, and wire metal atoms are accelerated. This is what we call heat. The simplest way to see it is plugging plain not isolated wire to battery- after a second it will be so hot, you won't be able to hold wire in hand.. It happens all the time, not just after plugging plain wire making short circuit, but it's remaining unnoticed, heating of wire is not significant (it's spread across time). If you see photons emitted by Tesla coil, they escaped system entirely, and energy is lost. In free device generator (if it would exists) you should see no radiation to environment. It's direct sign of lost of energy.
  24. If you will call somebody else linkable library function, you won't learn anything, no? If it's homework, and teacher ordered you to implement compression/decompression without using 3rd party library, you should better listen him..
  25. We can see particle traces in diffusion cloud chamber. http://en.wikipedia.org/wiki/Cloud_chamber I have build couple such devices. The simplest one cost me equivalent of ~15 usd (40x25x25 cm size). In USA/EU might be more. Single running cost (price of 1 kg dry ice) is ~3 usd here. Result is like in this video: http://www.youtube.com/watch?v=Efgy1bV2aQo In the video narrator is mentioning alpha particles thick traces. They are Helium-4 nucleus. Beta radiation mentioned is electrons (beta decay-) or positrons (beta decay+). Cosmic rays can be muons, pions, kaons etc.
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