How does wave reflection work?

[iScience]

this is a silly question but, how exactly does the reflection of a wave work? explain to me the mechanics/physics please.

say you have a rope attached to a wall at one end. and at the other end there is a wave generator. a wave is generated and right when the wave front hits the wall, what happens?

 

[Simon Bridge]

A wall, in the kinds of model you have just used, is a rigid, immobile, object.
When you push or pull on a wall, it generates a reaction force equal and opposite to the push or pull.
When a wave hits the wall, it pushes and pulls on the wall - i.e. a transverse wave tries to make that spot on the wall move side to side - so...
(you should be able to take it from there.)

 

[Bobbywhy]

Have a look at this, specifically the “law of reflection” section:

"Waves - Lesson 3
Behavior of Waves
Previously in Lesson 3, the behavior of waves traveling along a rope from a more dense medium to a less dense medium (and vice versa) was discussed. The wave doesn't just stop when it reaches the end of the medium. Rather, a wave will undergo certain behaviors when it encounters the end of the medium. Specifically, there will be some reflection off the boundary and some transmission into the new medium.
But what if the wave is traveling in a two-dimensional medium such as a water wave traveling through ocean water? Or what if the wave is traveling in a three-dimensional medium such as a sound wave or a light wave traveling through air? What types of behaviors can be expected of such two- and three-dimensional waves?"

http://www.physicsclassroom.com/Class/waves/u10l3b.cfm