A distant star has a transverse speed (perpendicular to our line of sight)of 30,000 km/s with respect to Earth.Its spectrum has an absorption line at a frequency of 5.00 x 10¹⁴ Hz.What is the frequency of that line as observed on Earth? A)4.50 x 10¹⁴Hz B)4.90 x 10¹⁴Hz C)4.97 x 10¹⁴ Hz D)5.00 x 10¹⁴ Hz E)5.04 x 10¹⁴ Hz

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The correct answer is C.The Doppler shift formula is:$$f_o = f_s (1 - v/c)$$where:* $f_o$ is the observed frequency* $f_s$ is the source frequency* $v$ is the relative velocity between the observer and the source* $c$ is the speed of lightIn this case, the source frequency is 5.00 x 10^14 Hz and the relative velocity is 30,000 km/s. Plugging these values into the formula, we get:$$f_o = 5.00 x 10^{14} Hz (1 - 30,000 km/s / 3 x 10^8 km/s)$$$$f_o = 4.97 x 10^{14} Hz$$Therefore, the observed frequency is 4.97 x 10^14 Hz.

A Distant Star Has a Transverse Speed (Perpendicular to Our