Hints:

 

b.1)

 

If you cannot solve this by calculus, the area is:

A L ,

p

where A is the amplitude of the wave and L is the wavelength.

 

 

 

b.2) Calculate the volume of this 1 m wide section, and use the formula for kinetic energy:

m v2 ,

2

where v is the speed of the wave. Note that 1 m3 of water contains 1000 kg of water!