On the runway 1200 meters long, the aircraft acquires a speed of 50 m / s. At what speed does the plane pass

On the runway 1200 meters long, the aircraft acquires a speed of 50 m / s. At what speed does the plane pass a point located at a distance of 400 m from the starting point?

Distance traveled by the plane during takeoff:

S = (V² – V0²) / 2a, where S is the length of the runway (S = 1200 m), V is the final speed of the aircraft (V = 50 m / s), V0 is the initial speed (V0 = 0 m / s), a – aircraft acceleration.

a = V² / 2S = 502 / (2 * 1200) = 2500/2400 = 1.04 m / s2.

Speed after passing 400 m of the runway:

V² = 2a * S.

V = sqrt (2a * S) = √ (2 * 1.04 * 400) = √ (832) = 28.84 m / s.

Answer: After passing 400 m, the plane will acquire a speed of 28.84 m / s.