The car shown below is approaching the observer at a speed of 40 m/s. The car honks its horn at a frequency of 1,000 Hz, and the speed of sound in air is 340 m/s. What is the frequency that the observer will hear?

observed frequency F = 1133.33   Hz

Explanation:

given data

car speed = 40 m/s

horn frequency = 1,000 Hz

speed of sound in air =  340 m/s

solution

We use here Doppler's Effect formula for unknown frequency that is

observed frequency F =     ...................1

here v is velocity of sound in air and Vl is velocity of observer and and Vs is velocity of source and Fs is actual frequency

put here value and we will get

observed frequency F =  

observed frequency F = 1133.33   Hz

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000