The train car was pierced by a bullet flying at a speed of 900 m / s perpendicular to the car. Due to the movement of the car

The train car was pierced by a bullet flying at a speed of 900 m / s perpendicular to the car. Due to the movement of the car, the inlet and outlet of the bullet are displaced relative to each other by 3 cm. What is the speed of the car? wagon width 2.7 m.

Let the width of the carriage be l. Let’s find out the time: t = l / v = 2.7 / 900 = 0.003 s It is logical that in such a time the train car has traveled 0.03 meters. v = s / t => v = 0.003 / 0.03 = 10 m / s = 36 km / h.