A spaceship is traveling at a speed of 15,000 km/s from planet "B" toward planet "A." The spaceship sends out a signal with a wavelength of 4 m.If astronomers living on planets A and B measure the radio waves coming from the spaceship, what wavelengths will they measure?
A) Planet A measures 6 m, and planet B measures 2 m.
B) Planet A measures 2 m, and planet B measures 6 m.
C) Planet A measures 4.2 m, and planet B measures 3.8 m.
D) Planet A measures 3.8 m, and planet B measures 4.2 m.
E) Both Planet A and planet B measure 4 m.

Question

Quizplus · Accepted Answer

Due to the Doppler effect, the wavelength shortens (blue shift) as the spaceship approaches planet A and lengthens (red shift) as it moves away from planet B.

A Spaceship Is Traveling at a Speed of 15,000 Km/s