A tidal bore may occur when the ocean tide enters an estuary against an oncoming river discharge,

Question:

A tidal bore may occur when the ocean tide enters an estuary against an oncoming river discharge, such as on the Severn River in England. Suppose that the tidal bore is 10 ft deep and propagates at 13 mi/h upstream into a river which is 7 ft deep. Estimate the river current in kn. Fig. P10.87