  The hydrokinetic model and the scheme of dynamical freeze out proposed
earlier for the RHIC energy are extended to lower colliding energy for
non-vanishing baryon chemical potential. In this case a new two-phase equation
of state is applied where baryon-rich hadronic matter is described within
modified relativistic mean-field theory. As an example, the approach is
employed for analyzing pion and kaon spectra and interferometry radii of Pb+Pb
collisions at laboratory energies 40 and 158 AGeV. A good agreement is observed
for the transverse mass dependence of the longitudinal radius for both energies
studied. The transverse radii $R_{out}, R_{side}$ reproduce experiment at
$E_{lab}=$158\ AGeV but at $E_{lab}=$40\ AGeV there is a marked (20 \%)
difference from experimental points. This discrepancy is more noticeable in
analysis of the ratio $R_{out}/R_{side}$. Nevertheless, considered examples of
application of the hydrokinetic model with equation of state including the
first order phase transition are quite successful and further development of
the model is required.
