An aircraft taxiing at a constant speed is an example of Newton's First Law of Motion, also known as the Law of Inertia.

Here's why:

* Newton's First Law: An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

* The Taxiing Aircraft: The aircraft is in motion (taxiing) at a constant speed. This means it's not accelerating (changing its speed or direction). The forces acting on it are balanced:

* Thrust from the engines: Propelling the aircraft forward.

* Drag from the air: Resisting the aircraft's motion.

* Friction from the wheels: Resisting the aircraft's motion.

* Weight of the aircraft: Pulling it down.

* Normal force from the ground: Pushing the aircraft upward.

Since these forces are balanced, the aircraft continues moving at a constant speed in a straight line.

Let me know if you have other physics questions!