A wave pulse traveling on a string is considered a transverse wave because the direction of the pulse's displacement is perpendicular to the direction of the wave's propagation.

Here's a breakdown:

* Transverse Wave: In a transverse wave, the particles of the medium oscillate perpendicular to the direction the wave travels. Imagine a rope tied to a wall. If you shake the rope up and down, you create a wave that travels horizontally along the rope. The rope itself moves up and down (perpendicular to the direction of the wave).

* String Pulse: When you displace a section of a string, you create a pulse that travels along the string. This pulse causes the string particles to move up and down, which is perpendicular to the direction the pulse travels along the string.

In contrast, a longitudinal wave has oscillations parallel to the direction of propagation. Think of a slinky. If you push and pull on the end, the compressions and expansions of the slinky travel along its length (the same direction as the wave).

In summary: The wave pulse on a string is transverse because the displacement of the string particles (up and down) is perpendicular to the direction of the wave's travel (along the string).