The sun's rotational period is 25 days at the equator. Given that the radius of the sun is 700,000 km, calculate the max velocity of approach or recession of the Sun's equator as viewed from Earth. Find the max change in wavelength of a spectral line due to the rotation and express it as a percentage of the rest wavelength of the line.(adsbygoogle = window.adsbygoogle || []).push({});

Relevant equations

Circular motion formula v = (2*pi*r)/period

Frequency = 1/period

wavelength = c/frequency

The attempt at a solution

Convert period into seconds

P = 2 160 000 sec

Convert radius of Sun into m

r = 7*10^7 m

v = (2*pi*7*10^7m)/2 160 000 s

= 2.04 m/s

frequency = 1/period

f = 1/ 2 160 000

wavelength = c/f

= 6.48*10^14 m

I'm not really sure what the question is asking beyond this

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# Astronomy : Velocity of approach of the Sun's equator

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