"Are you a worker?"
Interesting fact - the English word "robot" is a cognate of the Russian word for "work"
it should def. be accepted, because "рабочий" means almost always an industrial worker or a worker who engages in hard labour of one kind or another. other types of workers should be translated as "работник" (or something else depending on the context). for example, a social worker in Russian is "социальный работник"; medical worker -- медицинский работник.
in this case it is a noun (a nominalized adjective), but it can also be an adjective, which means working or related to work.
if in this sentence the word "рабочий" were an adjective, it would mean something like "are you functioning?".
You can say "Вы этот рабочий", meaning "You are this worker". But you won't use "это" like "Вы это рабочий".
So how would you ask if they are this particular worker? Would that still use этот?