This question is a bit tricky, as it depends on how you define "motion" and "speed".

Here's the breakdown:

* Motion implies a change in position. So, if an object is moving, it has a speed, which is how fast it's changing position.

* Speed is the rate of change of position. So, if an object's speed changes, it's changing its motion.

Therefore, it's not that motion *affects* speed; rather, motion and speed are intrinsically linked.

Here's why this is a bit of a wordplay issue:

* If an object is moving, it has a speed. So, motion *implies* a speed.

* If an object's speed changes, it's changing its motion. So, changes in speed *describe* changes in motion.

Think of it this way:

* You can't have motion without speed.

* You can't change an object's speed without changing its motion.

Let me know if you'd like to explore specific examples!