Translation:The employees are putting a carpet on the floor.
I find that "putting a carpet on the floor" is not specific about what the workers are doing with the carpet, whereas "putting carpet on the floor" (no "a") can only be that they are redoing the floor by covering it with carpet.
So "the workers are putting carpet on the floor" should definitely be accepted.
So... When people kładą something somewhere, is it Locative? I thought if it is "where to" (куда) rather than "where" (где), it would be Accusative ((((. Like, "siedzący na podłodze", but "kładący na podłogę". Is it always Locative when we put/place/move something somewhere, or is it specific for kłaść + na?
With such verbs as "kłaść", both versions make sense. Their focus is slightly different, but generally they mean the same. The Accusative form focuses on the action of putting the thing somewhere, the Locative form focuses on where the thing ends up as a result.
I think that the Locative one is more common, but that's only a guess.
Both answers are accepted.
I'm sort of surprised that podłoga is in the locative vs. the accusative here. "...Putting a carpet on the floor" is perfectly good English but my interpretation of it is "...onto the floor." This sentence could almost make me think the pracownicy are sitting na podłodze and they kładą dywan [into/onto someplace]. Is that not right?
The first image result for "na podłogę" is so the accusative phrasing is possible, but there must be more to know. Based on other sentences in the lesson, I wonder if using the accusative is just bad Polish. As for "na podłodze" image results, most are of people sitting on floors, but there's also a guy laying down tiles, so who knows.
Okay, don't cite me on that, as it's just my impression (as a native, but still), but it can imply, how "well" they are putting said carpet on the floor. You can just drop it on the floor still packed and rolled up (with accusative) or properly lay it to serve its intended purpose (with locative).
Of course in the case of a carpet most people would assume the second meaning anyway regardless of which of two cases you use, so sometimes it's interchangeable. Oh vey.
PS: "Na podłogę" can also mean "for (use on) floor". Your query for above image can refer to the tiles specifically, not an action.
all the first page results in google for "na podłogę" show "what materials to use for the floor" "tiles or wood what is better on the floor", "how to isolate, best material for the floor"
Also if "Kladę dywan na podłogę" - I just bought it and I place it unpacked on the foor Kładę dywan na podłodze - I cerefully put a carpet on the floor unroling it and lacing under the bed legs