Explanation:
Calculate the velocities by assuming incompressible flow and conservation of mass. v1 =0.22 m/s; v2 = 7.95 m/s. Mass flow rate = 6.3 x10-2 kg/s. Rate of change in momentum = 6.3 x10-2 kg/s x 7.7 m/s = 0.5 N. As you might imagine, such calculations are interesting for some firefighting applications.
