An aeroplane runs for some distance on the run way before taking off. Why?

Explanation

Aeroplane can flu if the lift due to pressure difference on the lower and upper face of the wings of aeroplane is sufficient to overcome the weight of aeroplane. To get the required lift, the aeroplane runs for some distance on the runway before taking off. Due to streamline shape of the wings of the aeroplane , teh velocity of air streams on the upper faace of the wings of aeroplane becomes more than the velocity of air streams on the lower face of the wings of aeroplane. As a result of it, the pressure becomes less on upper face than on lower face of the wings of aeroplane. This pressure difference increases with the increase in speed of aeroplane . when aeroplane running on high way attains sufficient speed, it gets required lift to fly.