A Spaceship, Moving Away from the Earth at a Speed

question 52

Multiple Choice

A spaceship, moving away from the Earth at a speed of 0.9c, shines a green laser backwards at Earth. An observer on Earth would see the light arriving at a speed of

• A) 0.1c and with an inverted frequency.
• B) more than c but less than 1.9c.
• C) c but at a shorter wavelength.
• D) c but at a smaller frequency.
• E) 1.9c and with a shorter wavelength.

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