4. A 55 m long, 65 cm high, monochromatic plane progressive wave at a depth of 7 m propagates towards the shore. Assume that the beach is straight and that the bottom contours and the crests of the incoming waves are parallel to the shoreline. Ignore reflection from the beach. Determine the following: a) The wave characteristics (L,T,C,H) at a depth of 2.5 m (9 points) b) The energy absorbed by 20 meters of beach length over 6 hours. (7 points) c) The wave height at the depth of 2.5 m, if you assume that 20% of the wave energy is lost as the wave propagates from a depth of 7 m to that of 2.5 m. Ignore energy losses as the wave propagates from deep water to the depth of 7 m. (9 points)