What is one function of a wedge as a type of simple machine?

A wedge primarily functions to separate materials. It is an inclined plane that converts a force applied to its wider end into a force that splits or cuts as the narrower end penetrates the material. This action is crucial in applications such as cutting wood with an axe or splitting objects apart.

The other options refer to different mechanisms that do not align with the specific definition of a wedge's function. Multiplying distance is characteristic of specific types of levers, changing the direction of force is associated with pulleys, and increasing speed doesn't directly relate to the fundamental purpose of a wedge, which is geared more toward separation and cutting rather than enhancing speed or efficiency. Thus, focusing on the function of separating materials distinctly clarifies the role of a wedge in simple machinery.