Undergrad Combination sink/source in one object

[nomadreid]

Is there any phenomenon (in physics: no wisecracks about human interactions ) in which A is attracted from further out to B until it gets close to B, whereupon A is repelled from B? (Sort of the opposite to the switch between the electromagnetic repulsion being overpowered by the strong force in tunneling.)?

 

[Orodruin]

The effective potential of any two-body problem in an attractive 1/r potential will display this behavior due to the angular momentum barrier.

 

[nomadreid]

Thank you, Orodruin. I will have to do a bit of research to find out precisely how this works, but you have put me on the right path.