The sensitivities of hurricanes to surface friction and the Coriolis parameter are studied using the axisymmetric version of the Goddard cloud ensemble model. The model uses an open boundary condition and Newtonian cooling. It is found that the hurricane can exist without surface friction, but its size is much larger than normal. Increasing surface friction drag coefficient leads to a reduction of the hurricane size in terms of the radii of maximum wind and maximum precipitation. It also leads to earlier onset of cyclogenesis and higher minimum surface pressure at the mature stage. The experiments show an optimal value of the Coriolis parameter, which corresponds to a latitude between 7.5 and 10 degrees from the equator, if the intensity is measured by minimum surface pressure. The interpretation of these findings will be offered.