Just as a side note. “Impulse” in physics is a force over a period of time. So it may confuse some people. Just worth noting.
Change in momentum (Or Impulse) = the force applied multiplied by the elapsed time
So I understand why you’re confused at the wording here because you’d consider deriving a proportion of that elapsed time into segments (frame time). But I guess that’s not what it does (Considering The Beej’s response).
…on the other hand…
If we consider that the Impulse is, as it stands, already taking into account that entire system of change… it, in itself, is the value of that computation. I suppose you would consider it to make sense if we were instead to say: “I am applying this impulse, not as a function of time, but rather the value of that function of time. Ergo, it has already been computed - Thus it’s an immediate and entire affect”
… Still. worth noting.