albertlee

v2 = u2+2as For the above equation, it was found by eliminating t from one of the below simultaneous equations, and substitute it into another euqation..... 1) v = at + u 2) s = ((v+u)/2)t where v = finally velocity a = acceleration t = time u = initial velocity s = displacement but who started this kind of equation? What kind of problem did this equation's inventor face upon which he forms this equation? I know it might be, because this equation contains much many information like acceleration, displacement, final/initial velocity, etc..., so it could much handy to use for solving problems, but however, if I see the equation alone, it makes no sense, since it is just another way of expressing v2 = (at + u)2........ I am just curious about it, because in one way or another, I can solve any physics problem till now without using that equation although my teacher told me it is much more handy since a long time ago... Any body? Albert

Respiration without oxygen = anaerobic respiration Respiration with oxygen = aerobic respiration

Do you all know there once was a big hacking war between US and China? in 2001? Albert

ANd more over, Amedeo first said that gas like hydrogen and oxygen was not formed as individual atom, but a single molecule of these, which was a confliction of Dalton's theory during that time, but how does his discovery of molecule and atom associating with his so-called Avagadro's law nowadays? or in another saying, how did he find out about the difference of atom and molecule? (During that time, atom and molecule basically meant the same thing) Albert

thx Firedragon52!!

It seems that coding from Microsoft Windows was much longer than Unix, and less effective than Unix ......... so, does that mean the engineers from Microsoft are less qualified than the ones from *nix?

then why he was named for this constant?

As stated in the topic, how did he find out the numbers as nowdays Avogadro's constant? Albert

Yes, but I found something quite absurd is some pupils in class say that Macintosh is faster than Windows on programming, making animations and images, etc........ ANd any way, I found that Mac is averagely more expensive than PC, why's that?

Any body?

Then, if you compare the performance of OS X on PowerPc 64 bits, and Windows Xp 64 bits on AthlonXP, which one is faster? I have tried using Mac OS X(32bits), and feels it just nearly never crashes while with same speed of x86 processor 32 bits for Windows, which has a tendancy of blue&white error screen.... Albert

Which one is faster? if both frequency are the same?

If I throw a stone(1 kg) upwards and the intial velocity is 14m/s, And Does that mean the acceleration is (14m/s)/s ? and the force is 14N? If so, how do i find out the time that I am exerting the force on the ball upwards? Secondly, I thought it must 1 second, because it never accelerates after intial volcity, and it is retarding due to the gravitational acceleration..... So what is the time I am exerting force on the ball upwards? Apreciate in advance Albert

Any way, I am not going to ask too many questions any more but any way, as long as I know how to find what and how many charges there are, thats more than enough A link to a simple and clear explanation : http://dl.clackamas.cc.or.us/ch104-07/polyatom1.htm ALbert

sorry for duplicating post, but any body to my previous message? THX IN ADVANCE

5614, but how, how can you determine the limit of Hs an element can have in covalent bonding?

To me, "dumb" means any one who has a lower IQ...... IQ is quite depending on individual rather than a group of people In my class, there is straight A grade guy who's considered as 'dumb', because he got totally different ideas than other...... New ideas are like new shoes, which hurt some feelings... Any way, Marie Curie was a blonde (I think) and she was the laureate of two nobel prizes!!! Albert

then why not NH5? more force pulling each other?

YT, what??????????? Every one told me that the polyatomic ion in combination with another mono-atomic ion has both covalent (for polyatomic ion) and ionic bonding...., but now you say the polyatomic ion is bonded in ionic? Any way, I am asking: why NH4 ion in covalent bonding will be more stable than NH3 in covalent bonding? Actually it appears not only in NH3 which strangely bonded in such way....like for eg, OH 1-, why it gives away one H? there is no point for this.... So, in my opinon, both OH and NH4 ion dont stay in this form individually since it is no reason scientifically for this, this ion only forms when there is energy exerting on them when in combination with other element in ionic bonding... and on the contrary, I may be wrong....thats why I am asking you guys who study chemistry in unversity Any body? thx Albert

so..... any way, the only thing I dont get yet is why NH4 ion in covalent bonding will be more stable than NH3 in covalent bonding? Albert

When H atom is near ammonia, does it loose electron to be attracted to the lone pair of N atom?

budullewraagh, are you answering my question: How is there an extra hydrogen cobining with NH3 in any way that makes an ion with a complete positive charge? ? what do you mean by "coordinate"? besides that, I know hydrogen always form covalent bond, but again, there is no need for NH3 to take up one extra hydrogen to share the electrons....... So again again again, How is there an extra hydrogen cobining with NH3 in any way that makes an ion with a complete positive charge? thx for the responds Albert