回复：回复：What mistake?

I guess you are really confused.

By "acceleration", one means the rate of change of speed. This is one variable, sampled over time. Power is the other variable, sampled over time.

By saying that two variables are related, one means that as one variable changes through time, the other changes as well. "Directly related" means it's a one-to-one, or bijective map, in the weak sense. In the strong sense, it would mean a linear relationship.

If V is going up in a constant rate, it means acceleration is unchanged. This variable is constant. Meanwhile, P is going up. A variable that's changing cannot have a direct relationship with a variable that's constant. Got it?

Why do we say that "acceleration" measures "rate of speed change"? First it's how it's defined in physics, period.

Second, in typical marketing schemas involving horse-power, it goes like this: this car has higher horse-power, therefore it goes from 0-60 in a shorter time. What does it mean to say "it goes from 0-60 in a shorter time"? That the average rate of speed change, or average acceleration number A, is larger. In other words, this statements goes "higher P => higher A". That's the point made in the article you quoted.

But I've demonstrated that P can go higher with A remaining constant, contradicting this type of claim.