
#1
Aug2711, 03:59 AM

P: 34

Hey So for those that don't know, I'm reading this from Atomic Physics, basically where they teach you how the size of a nucleus was determined by shooting alpha particles at it. due to repulsion an alpha particle can get only 'soclose' to nucleus(they're both positively charged), and the the soclose is labelled as point P, the closest to the nucleus and alpha gets.
So heres a formula they teach us to use: 1/2mv^{2} = kQq/r What is k called? what is the name of this constant, and what is it equal to since I was told it was the electric constant and went about solving it with that value, but at the back in the answer section they used the value 9x10^9!! Thanks guy!!! :D 



#2
Aug2711, 04:37 AM

Sci Advisor
HW Helper
Thanks
P: 26,167

hi kenshi64!
that's the Coulomb's law equation k (or k_{e}) is the Coulomb constant, 8.988 10^{9} Nm^{2}/C^{2} k = 1/4πε_{0} ε_{0} (not k) is the electric constant, also called the permittivity of the vacuum see http://en.wikipedia.org/wiki/Coulomb%27s_law and http://en.wikipedia.org/wiki/Electric_constant for more details 


Register to reply 
Related Discussions  
Show xa< epsilon IFF aepsilon < x < a+epsilon  Calculus & Beyond Homework  3  
U(f,P)  L(f,P) < epsilon proof!  Calculus  4  
Yet Another DeltaEpsilon  Calculus & Beyond Homework  10  
Is there a value for epsilon?  General Physics  3  
Coulomb's epsilon zero and its name  Classical Physics  4 