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Everything posted by HallsofIvy

  1. Why Pythagoras almost destroyed the world! And think of the trouble learning to count has caused!
  2. You were not "scolded or humiliated", you were told what the conditions of this forum are. You say "actually I have exactly 15 questions. I've done 10 of them". Excellent! Show us what you have done so we will know what you do understand and what you can do on them. Then we will know what help you need.
  3. Since this was originally posted two months ago: We have aBaCl2(aq)+bK2SO4(aq)→nBaSO4↓+mKCl(aq) Looking at that I see that there are "a" Ba atoms on the left and "n" Ba atoms on the right so we must have a= n. I see that there are "2a" Cl atoms on the left and "m" Cl atoms on the right so we must have 2a= m. Is that there are "2b" K atoms on the left and "m" K atoms on the right so we must have 2b= m. Finally I see that there are "b" SO4 ions on the left and "n" SO4 ions on the right so we must have b= n. That is, we have the four equations a= n, 2a= m, 2b= m and b= n. That is four equations in the four unknowns, a, b, m, and n. One difficult is that when the number of equations is equal to the number of unknowns there is typically a unique solution. But it is obvious that a= b= m= n= 0 is solution while we want non-zero values! If there is not a unique solution we can try to solve for all but one unknown in terms of that one. Let's try to solve for b, m, and n in terms of a. We have immediately that n= a and m= 2a. 2b= m= 2a so b= a and n= b= a. So if we arbitrarily take a= 1, b= 1, m= 2, and n= 1. We have BaCl2(aq)+K2SO4(aq)→ BaSO4↓+2KCl(aq)
  4. Archimedes is supposed to have said "Give me long enough lever and a place to stand and I can move the earth". The "place to stand" is crucial! When your strong man is pushing against the wagon what are his feet pushing against? When he is standing on the ground, outside the wagon, His arms are pushing the wagon one way while his feet are pushing the ground in the opposite direction. Of course the earth is so large it isn't going to move so it is just the wagon that moves. When he is standing in the wagon his arms are pushing the wagon one way and his feet are pushing the wagon the opposite way. it is a stalemate! Nothing moves.
  5. "In the sea" or "over the sea". That is, do you mean the pressure in water or air? Assuming the latter, which is more common, warmer water warms the air above it so that the air expands and rises.
  6. Many people, who have little or no experience in science, look at a book or paper on science and see what looks, to them, like gibberish. Unfortunately, a few people conclude from that, that if they write gibberish, they are writing science.
  7. I'm wondering if "CuriouOne"s difficulty is with the English language. For example, in another thread (which was closed or I would responded there) "CuriosOne" repeatedly referred to "smaller pennies" where the correct phrase would be "fewer pennies". It is very strange that he posts questions about Calculus but makes0 basic algebra or even arithmetic mistakes.
  8. HallsofIvy


    What help do you need or want? In order to help you we need to know what you already understand about this problem, what you are able to do, and what you are not able to do. In order to know that, we need to see what you have tried yourself. Surely you did not just post this without trying at all yourself? Please show us what you have tried.
  9. The first one is pretty close to being trivial! H2O is the only "acid" in the equation!
  10. As t goes to infinity the exponential goes to 0. Because the exponential is always positive and is subtracted, the "limiting charge" is when that exponential goes to 0 so is EC. You want to find t such that Q= -exp{-t/RC+ ln(EC)+ EC= -ECexp{-t/RC}+ EC= 0.99EC that is the same as -ECexp{-t/RC}= -0.01EC or exp{-t/RC}= 0.01.
  11. Now I'm hoping that all of your posts are silly jokes. Otherwise, you not only do not know but are refusing to learn from those that do know. And you have asserted repeatedly that "no one knows"! I think I am through responding to any of your posts. It does no good,
  12. So you posted this whole thread as a joke? I suspected that from the start. I didn't think a person would use so many words without having any idea what they mean! (And the word is "cease", not "seize"!)
  13. It looks to me like you don't know what "base" means here.
  14. To block radiation, use a lead plate. To measure radiation, use a geiger counter.
  15. No, I am not. But I think the term you want is "branching" rather than "non-linear".
  16. The "Multiverse" and "proto-universe" are hypotheses with very little experimental verification. Do you have more to say about them?
  17. Velocity and acceleration are "difference quotients"!
  18. That's obviously Wile E. Coyote who ran into the "monolith" while chasing the road runner. It even has "ACME" at the bottom!
  19. If we allow 1 as a prime number, we would no longer have "unique prime factorization". Now, 12= (2^2)(3). If we allow 1 as a prime number, 12= (1)(2^2)(3)= (1^2)(2^2)(3)= (1^3)(2^2)(3)= (1^4)(2^2)(3)= ....
  20. I believe that " this sentence is about itself being informative" WAS an example. Unfortunately, I have no idea what the sentence means! I suppose you could write "p-> (p-> i)" where "p" is "this sentence" and "i" is "is informative".
  21. Frankly it appears that you do not know what "limits" are! If you did, you would know that "24.999....." IS exactly 25. Taking a limit does NOT "involve two points", it involves infinitely many points. Taking "the limit as x goes to a" involves all the points between [tex]a- \delta[/tex] and [tex]a+ \delta[/tex] and, no matter how small [tex]\delta[/tex] is, there are infinitely many points between those points.
  22. Yes, we, and animals and plants, take in water. I don't know about the rest of you but I pee frequently. That fluid goest to the local sewer system where "pollutants" are taken out and the clean water is "returned to the wild". Similarly, when animals urinate onto the ground, the water evaporates and forms clouds where it the falls as rain and replenishes rivers, lakes, and reservoirs. Much the same is true of plants- water plants excrete returns, eventually, to the sky. That is referred to as the "wate cycle". I thought everyone, beyond the fifth or sixth grade, knew that!
  23. Oh, I see. You are asking this question because you don't understand how to calculate probabiities. What you are saying is equivalent to "If I cross the street in the middle of the block, there are two things that can happen- either I get killed or I don't. Therefore the probability of getting killed is 1/2." Given an infinite number of universes, we can still calculate what percentage of them have a given property.
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