OK... this question does not have a specific topic... anyway...
Why is it that if a mosquito or a fly in a moving vehicle or elevator always stay in the enclosed space, suspended in the air and do not collide with the walls enclosing it?? :confused:
Well maybe I'm really dumb :p

Because the air is also moving at the same speed as the car. The fly or mossie will hit the glass, land on the dash, etc because it is moving in that air. If you open the window and the fly goes outside the enclosed space it will not be next to the car for very long (unless you are driving at 1 or 2 mph in traffic)

ANother example of this phenomenon: it is not unusual to see a fly buzzing around the cabin of a jet liner which may itself be traveling at 600 MPH. Next time you're on a plane, try tossing a ball or small object up in the air - note that it doesn't go crashing towards the back of the plane at 600 MPH but rather just falls back into your lap exactly as if you were seated in your stationary living room at home.

The reason why this works is a concept called "inertia," which says that objects that are moving will continue moving in the same direction and at the same speed unless some external force acts upon it. In the case of the mosquito in the car, once it (and you) are traveling at 60 MPH relative to the road in the enclosed car there is no force acting to slow it (or you) down, and consequently you each perceive each other as being stationary. Another interpretation of this phenomenon comes from Galileo, who determined that all motions are relative - that is, there is no such thing as an absolute velocity. Hence if the car is moving at 60MPH relative to the road, as far as the occupants of the car are concerned they may as well be stationary and the rest of the world is moving at 60 MPH in the opposite direction.

Hope this helps!