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Distance of closest approach


If an alpha particle with a kinetic energy Ea is fired directly towards a gold nucleus it will feel a repulsion which increases as it gets closer.
When all the kinetic energy has been converted to potential energy the alpha particle (charge q) has reached its distance of closest approach (dc) and comes to rest.

At that point : Ea = qVE =(1/4peo)qQ/dc


Distance of closest approach (dc) = (1/4peo)qQ/Ea
 
 
 
© Keith Gibbs 2010