Have you ever seen in your car a mosquito? it's not capable of going 60 mph. How come it can still keep up with the car as if it weren't trying For instance, a fly is staying at the same spot, then your car suddenly moves forward at a rate of 60 mph. The mosquito IS staying at the same spot but for some reason it moves along with the car as if nothing happened.
 A: The air inside the car moves transiently as the car speed up (is being pushed by the rear of the car, sits, etc), if this happens slow enough this will occur without much turbulence or wind-like movements. The mosquito is pushed by the air (assuming he is flying), so in his frame of reference, relative to the inside of the car, he is still moving slow. Only a person in the street outside the car will measure a mosquito speed of 60 mph
A: Actually, there are two factors responsible for helping the mosquito keep up with the car:


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*If we consider the car to be already moving at 60mph, the air inside the car is also moving at 60mph. As the wings of the mosquito are subject to air resistance, its inertia will be resisted by the forward moving air, until the mosquito itself attains the constant velocity 60mph.

*If the car is accelerating, the situation illustrated in the image below will apply. The acceleration will cause more air to collect at the back of the car than in front. Therefore, the density of air at the back will be more. And hence, to move back, the mosquito will have to displace more air per unit volume than it will have to move forward (or remain stationary). So, this difference in densities of air in different sections of the car will help mosquito keep up with the car.

