  We discuss how the virtuality of the struck particle may affect the final
state interactions in electron-nucleus scattering. The extent to which short
range correlations inhibit rescattering taking place within the range of the
repulsive core of the NN interaction is quantitatively analyzed. The possible
modifications of the nucleon-nucleon scattering amplitude associated with the
virtuality is also studied, within the framework of a nonrelativistic model.
The results suggest that the on shell approximation can be safely employed in
the kinematical region relevant to the analysis of the available inclusive data
at large momentum transfer and low energy loss.
