Author Question: A plane flies toward a stationary siren at 1/4 the speed of sound. Then the plane stands still on ... (Read 101 times)

jessicacav · **on:** Jul 29, 2018

A plane flies toward a stationary siren at 1/4 the speed of sound. Then the plane stands still on the ground and the siren is driven toward it at 1/4 the speed of sound.

In both cases, a person sitting in the plane will hear the same frequency of sound from the siren. A) True
B) False

Question 2

A stationary siren emits sound of frequency 1000 Hz and wavelength 0.343 m. An observer who is moving toward the siren will measure a frequency f and wavelength for this sound such that

A) f > 1000 Hz and > 0.343 m.
B) f > 1000 Hz and = 0.343 m.
C) f > 1000 Hz and < 0.343 m.
D) f = 1000 Hz and < 0.343 m.