The car in the picture is honking its horn at 484 Hz. Which statement is true?

Person A will hear the horn at the same frequency as person B

Person A will hear the horn at a lower frequency than person B

Person A will hear the horn at the actual 484 Hz frequency

Person A will hear the horn at a higher frequency than person B

the ture are b and d

Explanation:

This is a Doppler effect exercise, suppose person B is inside the moving car and person A is on the street, motionless

The expression for the doppler effect of a moving source is

                 f´ = f (v / (v ⁻₊ )

where the negative sign is for car moving towards the observer

person B who is in the vehicle does not have relative movement with respect to the source, so he hears the real frequency of the sound f = 484 Hz

person A if he hears a different sound

             f´ = 484 (340 / (340 ⁻₊ v_{s}))

so if you are approaching in a vehicle you hear a higher frequency

if the vehicle drives away, you hear a lower frequency

with these results let's review the claims

a) False. They listen to different frequencies

b) true. If by car you drive away

c) False The vehicle moves with respect to A so the frequency changes, person B who is in the vehicle if he hears the actual frequency

d) true if the vehicle is approaching