the wave equation for a tsunami wave is x(l) = -A sin(6.28 l/ k).?

Question

the wave orignates at a distance of 200km from the shore A=.5 , k=200 . find the maximum hieght of the wave.. it gets compressed till a distance of 2km from the shore ..

Answer 1

The waveform for a tsunami will be more like the form h = Acos 2π(t - x/v) until the seafloor starts to rise and the hydraulic jump factor comes into play. My fluid mechanics is pretty rusty from years of disuse, but you need a better predictive equation than you have presented here.

Answer 2

The maximum value of the negative sine function occurs when the argument is a multiple of (3π/2), since sin[n*(3π/2)] = -1, that max value is A. Then, equate your argument 6.28*l/k to n*3π/2; to find the distances at which the wave is max. However, the max is always A.