Why reaction force must exist

In what direction does the medium move relative to the direction of the wave? explain.

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

Agas contained within a piston-cylinder assembly undergoes three processes in series: process 12: compression with pv= constant from 1 bar and 1 liter to 4 bar. process 23: constant pressure expansion to 1 liter. process 31: constant volume calculate the pressure and volume at each state, and sketch the processes on a p-vdiagram labeled with pressure and volume values at each numbered stat