The particles vibrate perpendicularly to the direction that the wave travels.
Hope this helps!
Answer:
perpendicular
Explanation:
There are two types of wave motion.
When the articles of medium vibrate in the perpendicular direction of the wave propagation, it is called transverse wave motion. For example, light rays
When the particles of medium vibrate in the same direction of wave propagation, it is called longitudinal wave motion. For example, sound waves.
