The mechanical wave that moves at right angles to the direction of the wave's energy transfer is called a transverse wave.

Here's a breakdown:

* Transverse wave: The particles in the medium oscillate perpendicular to the direction the wave travels. Imagine shaking a rope up and down – the wave travels horizontally, but the rope segments move vertically.

* Longitudinal wave: The particles in the medium oscillate parallel to the direction the wave travels. Think of a spring being compressed and released – the compression and expansion travel along the spring, and the spring coils move back and forth in the same direction.

Examples of transverse waves:

* Light waves

* Electromagnetic waves

* Waves on a string

* Water waves (to some extent)

Let me know if you'd like more detail on any of these!