  Using a hydrodynamical model we study how the order of phase transition in
the equation of state of strongly interacting matter affects single particle
spectra, elliptic flow and higher order anisotropies in Au+Au collisions at
RHIC (sqrt{s_NN}=200 GeV energy). We find that the single particle spectra are
independent of the order of phase transition and that the fourth harmonic
v_4(p_T) shows only a weak dependence in the p_T region where hydrodynamics is
expected to work. The differential elliptic flow, v_2(p_T), of baryons shows
the strongest dependence on equation of state. Surprisingly the closest fit to
data was obtained when the equation of state had a strong first order phase
transition and a lattice inspired equation of state fits the data as badly as a
purely hadronic equation of state.
