物理phy~~~~~~~

Since the wave travels from left to right, the position of particle d will give an indication of the previous position of particle c. That is, particle c just returns fromthe max position on the left side of its equilibrium position. Hence, it is moving towards the right.

Similarly, by comparing the position of particles g and f, particle f just returns from the right of the equilibrium position, hence it is moving towards the left.

The answer is thus option C

可唔可以用中文呀~唔該