Are "how", "why" or "is it possible" good for a research question?
If you already have a lot of research in your area, and you can use that to build up a case of inference, then you end your literature study and inferences with a hypothesis stating that "if all we know so far is true, then the following should also be true". That's your hypothesis.

If you don't have any knowledge to build upon, there is not previous experiences in your field (highly unlikely, but still possible), then you would instead use a research question. Of course, you could also use a research question if you are too lazy to study and do your literature study properly, or if you don't have the ability to puzzle together information into a case of inference. 

So if you're sitting in a closed off room and you have no idea what is outside the room and you don't have anyone to ask about the conditions outside of your room, then you can ask research questions. For example, is it raining outside of the room? To answer the question, maybe it would be possible to put a stick through a hole in the wall (assuming you are not able to look out) and if it is wet when it comes back inside then maybe it is raining. 

But how do you know that rain causes sticks to get wet? In this case, maybe you should instead collect information about sticks, and how their properties can change, where you find a research article stating that if you put sticks out when it's raining then they become wet. So you would instead build a case of inference and say that "sticks become wet if they are put in the rain", "it is not raining in this room", "if I put a stick outside of the room and if it is wet when I take it back inside, then it is raining outside". Then you do your experiment to test your hypothesis in this case (not research question), and it turns out that when you open a small hole in the wall, water is just gushing in. So you have to put up a new hypothesis and say "water is gushing in when it has a high pressure" and you end up explaining that your room is 1000 m below the surface of the sea, after many new articles with many new hypotheses, etc.

So in your case, you are asking "what is a good research question", and the answer is "any question that examines an area without previous knowledge is a good research question". If there is already knowledge that you can use to build upon, you would use that knowledge to state a hypothesis, and that is a much more efficient and reliable way to go about research. So you really shouldn't aim to get a research question, you should aim to avoid research questions.