The Amplitude does not change otherwise energy conservation is violated, since enrgy delivered by wave is proportional to (amplitude)^2. This may appear to be the case when waves on the sea approach the beach... but actually what is happeneing is the waves are becoming steeper as the wavelength...
With regard to your question about ke rockets and fuel... there is no "absolute" value of kinetic energy... we can only observe changes. W = fd is not really correct. Should be delta W = delta (Fd). Is it true that all observers, irrespective of their frame of reference would be able to...
Wk= Work done in accelerating object
Work done = Force x distance
If body a is traveling v m/s after 1 second, it is intuitive that it would be traveling with an average speed of v/2 m/s, so in one second it will travel a distance of v/2 m.
Now if body B was accelerated under the...