Here's why:

* Wave speed is determined by the medium: The speed of a wave depends on the properties of the medium it travels through. For example, sound waves travel faster in solids than in liquids, and faster in liquids than in gases.

* Amplitude is a measure of energy: Amplitude refers to the maximum displacement of a wave from its equilibrium position. A larger amplitude means the wave carries more energy, but it doesn't affect how fast the wave travels.

Think of it like this:

Imagine a rope tied to a wall. If you shake the rope gently, you'll create a small-amplitude wave that travels down the rope. If you shake the rope vigorously, you'll create a large-amplitude wave. However, in both cases, the speed at which the wave travels down the rope will be the same, determined by the properties of the rope itself.

Key takeaway: While amplitude and speed are both important properties of waves, they are independent of each other.