The fly in the car. Is it flying?

Not sure if this was asked before. I'm not a math genius/person like most of you here. I just have this question that i've always wondered about and though.. let me ask the math people how it works.

Anyways, the scenario is.

While travelling in a car doing 120km/h. There is a fly in the car flying in the air (in one spot just hovering). Is the fly flying at 120km/h ? or is it just hovering? Why is that? If the fly is not moving himself at 120km/h , why does it not smash into the back window with the forward momentum of the car?

Just a interesting one i've always wanted to know.

Thanks

via Recent Questions - Mathematics - Stack Exchange http://math.stackexchange.com/questions/291301/the-fly-in-the-car-is-it-flying