do all waves obey the Law of Reflection?

Question

homework question =)

Answer 1

Yes, if they found a device which can reflect.

If a device absorbs all the wave as water absorbs some infrared radiation, there will be no reflection

Answer 2

Only when you can use the approximations of geometrical optics, which is the case when the linear dimensions of the apertures and obsticles on the waves path are far greater than the wavelength.

Also, if the 'mirror' is moving, the law of reflection is not valid.

All the waves I've learned off exibit this property:
1) mechanical waves (sound waves and surface waves on liquids);

2) electromagnetic waves (radio, microwave, infrared, light, ultraviolet, but the wavelength of the X-rays is of the same order of magnitude as the lattice constants of solids, and for gamma even smaller, so hard to find a mirror);