A distant galaxy is simultaneously rotating and receding from the earth. As the

Question

A distant galaxy is simultaneously rotating and receding from the earth. As the drawing shows, the galactic center is receding from the earth at a relative speed of uG = 1.80 × 106 m/s.Relative to the center, the tangential speed is vT = 0.340 × 106 m/s for locations A and B, which are equidistant from the center. When the frequencies of the light coming from regions Aand B are measured on earth, they are not the same and each is different from the emitted frequency of 8.476 × 1014 Hz. Find the measured frequency for the light from (a) region Aand (b) region B. (Give your answer to 4 significant digits. Use 2.998 × 108 m/s as the speed of light.)

Explanation / Answer

A) Tangential speed at A is toward earth:
v = uG - vT =1.46E6 m/s
ß = v/c = 4.8699E-3
fA/f0 = sqrt((1+ß)/(1-ß)) = 1.0048818
fA = 8.517378E14 Hz

B) Tangential speed at B is away from earth:
v = -2.14E6 m/s
ß = v/c = -7.13809E-3
fB/f0 = sqrt((1+ß)/(1-ß)) = 0.9928872
fB = 8.4157119E14 Hz

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.