  I present time-dependent analytical solutions of quasi-steady shocks with
cooling, where quasi-steady shocks are objects composed of truncated
steady-state models of shocks at any intermediate time. I compare these
solutions to simulations with a hydrodynamical code and finally discuss
quasi-steady shocks as approximations to time-dependent shocks. Large departure
of both the adiabatic and steady-state approximations from the quasi-steady
solution emphasise the importance of the cooling history in determining the
trajectory of a shock.
