A car is parked 19.0 m directly south of a railroad crossing. A train is approac

Question

A car is parked 19.0 m directly south of a railroad crossing. A train is approaching the crossing from the west, heading directly east at a speed of 50.0 m/s. The train sounds a short blast of its 315-Hz horn when it reaches a point 16.0 m west of the crossing. What frequency does the car's driver hear when the horn blast reaches the car? The speed of sound in air is 343 m/s. (Hint: Assume that only the component of the train's velocity that is directed towards the car affects the frequency heard by the driver.)

I posted this question once and did not get the correct answer and they did not show their work! Therefore I had know idea what they did to even get the answer they posted. If someone could please help me out that would be great! Thanks

Explanation / Answer

To start off, you need to know the relative velocity of the train to the car when the train is 16m.west of the crossing.
The angle will be 45 degrees, as both the car and train are at that time, 19m. from the crossing.
(cos 45) x 50m/sec = 35.35m/sec. towards the car, at that instant in time.
((343 + 35.35)/343) x 315Hz = 347.46Hz. perceived by the car's driver.

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