Problem For Structure of Nuclei -- Enigmatic !

[aliz_khanz]

Question :- calculate the distance of closest apprach for a head on collision between 5.30Mev alpha particle and nucleus of a copper atom?

Answer
The distance of closest
approach is given by

d= _______qQ_______
4*pie*e0*K base alpha

= ____________2*29*(1.60*10^-19C)^2_______
4*3.142*8.85*10^-12C^2/Nm^2*5.30MeV*1.60*10^-13J/MeV

= 1.4 * 10^ -6 aNSWER..........

NOW I AM CONFUSED HERE ABOUT ONE THING AND ITS EATING ME ALIVE.....FROM WHERE DID 1.60*10^-13J/MeV CAME ? I HAVE USED COLUMB'S LAW !

[Hepth]

its the conversion between MeV and joules. Both are energy units.

[bcrowell]

FROM WHERE DID 1.60*10^-13J/MeV CAME ? I HAVE USED COLUMB'S LAW !

It's the fundamental charge, e, expressed in unusual units.