Alpha particle in gold foil scatering experiment

[asadpasat]

Homework Statement

How close does the alpha particle gets to the nucleus in gold foil scatering experiment?

Homework Equations

Ek = 2.0 MeV
W=F delta x
F=(kq1q2)/r^2
W=(kq1q2)/r
E=W=(kq1q2)/r

The Attempt at a Solution

E= (k(79)(2) e^2)/r
2.0MeV= (k(158)e^2)/r
2,000,000 eV = 8.99 Wm^2 c^-2 ((158) e^2) / r
2,000,000 eV convert by multiplying by 1.6 x 10^-19 J/ eV
r = 8.99 x10^ 9 Nm^2/c^2 (158) (1.6x 10^-19 c)^2 / 2,000,000 ev
r = 1.13 x 10^-13

I made somewhere mistake as the answer should be around 4 not 1.13 .
Any input appreciated

 

[rude man]

Homework Statement

How close does the alpha particle gets to the nucleus in gold foil scatering experiment?

Homework Equations

Ek = 2.0 MeV
W=F delta x
F=(kq1q2)/r^2
W=(kq1q2)/r
E=W=(kq1q2)/r

The Attempt at a Solution

E= (k(79)(2) e^2)/r
2.0MeV= (k(158)e^2)/r
2,000,000 eV = 8.99 Wm^2 c^-2 ((158) e^2) / r
2,000,000 eV convert by multiplying by 1.6 x 10^-19 J/ eV
r = 8.99 x10^ 9 Nm^2/c^2 (158) (1.6x 10^-19 c)^2 / 2,000,000 ev
r = 1.13 x 10^-13
I made somewhere mistake as the answer should be around 4 not 1.13 .
Any input appreciated

How about dividing by Joules instead of eV in your last equation?