A storm generates large waves in the Pacific Ocean. On november 25, 208, 6pm, swell with a wave height of…

A storm generates large waves in the Pacific Ocean. On november 25, 208, 6pm, swell with a wave height of 5m reaches an exposed location at the coast of Southern California. At 6 am of the next day, the wave height is 4m. The water depth within 100km of the coast is 1000m and 3000m everywhere else. All waves have a steepness of ak=0.25.
a) How far offshore were the waves generated by that storm?
b) At what date and time do waves with a height of 2m reach the same location at the coast?
c) How long does it take a tsunami with a wave length of 120km to travel the same distance (travelling perpendicular towards shore)?