Question

I understand that it will be higher frequency—pleasure explain what the wavelength/wave speed will be. I put this part in bold so you can see.

A siren sounds on a stationary ambulance. As compared to a stationary observer, an observer who is driving towards the ambulance at a constant speed would measure the sound wave produced by the siren to have:

i. a higher frequency, shorter wavelength, and the same wave speed.

ii. a higher frequency, shorter wavelength, and a faster wave speed.

iii. a higher frequency, the same wavelength and the same wave speed.

iv. a higher frequency, the same wavelength, and a faster wave speed.

Answer 1

Answer : (i) a higher frequency, shorter wavelength, and the same wave speed.

Since the medium through which the sound is traveling is the same - Thus the speed of the sound doesnt change which means the wave speed remains the same.

Now according to relation : Wave speed = Frequency x Wavelength.

Here, an observer who is driving towards the ambulance at a constant speed would measure the sound wave produced by the siren to have higher frequency. And, From above relation - Since the speed of wave remains same - So, the wavelength will be shorter.