Here's why:

* Wave speed depends on the medium: The speed of a wave is determined by the properties of the medium it's traveling through. These properties include:

* Density: Denser mediums tend to slow down waves.

* Elasticity: More elastic mediums (those that can deform and return to their original shape) allow waves to travel faster.

* Liquids vs. Solids: Solids are generally denser than liquids, but they are also significantly more elastic. This means the increased elasticity of the solid more than compensates for its increased density.

Example:

Imagine a ripple on the surface of a pond (liquid) that reaches the edge where there's a solid rock. The ripple will speed up as it transitions from the water to the rock.

Important Note: This is a general rule. The specific speed of a wave can vary depending on the exact types of liquid and solid involved, as well as the frequency of the wave.