Okay, I've got another one for you guys.
An interstellar gas circles the core of earth's galaxy. If the wavelength of the light reflecting off the gas coming toward the earth is 499 nm, and the wavelength of light reflecting off the gas moving away from the earth is 501 nm, what is the speed of the gas?
A. 4.2 x 10⁴ m/s
B. 1.2 x 10⁵ m/s
C. 6.0 x 10⁵ m/s - Correct answer
D. 1.5 x 10¹¹ m/s
The explanation in the back is screwing with my understanding more than anything. I can get the correct answer just by using v=c(Δλ/λ (where Δλ=1nm and λ=500nm). But, then the answer says something about the velocity of the gas needing to be divided by two because of the round trip issue? That changes my answer to something that isn't available in A<->D. That really just confused the heck out of me.
Thanks.
An interstellar gas circles the core of earth's galaxy. If the wavelength of the light reflecting off the gas coming toward the earth is 499 nm, and the wavelength of light reflecting off the gas moving away from the earth is 501 nm, what is the speed of the gas?
A. 4.2 x 10⁴ m/s
B. 1.2 x 10⁵ m/s
C. 6.0 x 10⁵ m/s - Correct answer
D. 1.5 x 10¹¹ m/s
The explanation in the back is screwing with my understanding more than anything. I can get the correct answer just by using v=c(Δλ/λ (where Δλ=1nm and λ=500nm). But, then the answer says something about the velocity of the gas needing to be divided by two because of the round trip issue? That changes my answer to something that isn't available in A<->D. That really just confused the heck out of me.
Thanks.