The spectrum of a star's light is measured and the wavelength of one of the lines as the sodium's line is found to be 589 nm. The same line has the wavelength of 497 nm when observed in the laboratory. This means the star is:
Correct answer: A. Moving away from the earth
- A. Moving away from the earth
- B. Moving towards the north
- C. Stationary
- D. Revolving around the planet
Explanation
When the wavelength of star was measured it resembled to the wavelength of sodium having wavelength 589 nm and when the sodium line was observed in the lab, its wavelength was calculated it came out to be 497nm . this means the wavelength had increased and it increases when star moves away.
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Progressive waves transfer energy through oscillations, with wavelength, frequency, amplitude and wave speed related by v = fλ; sound speed depends on the medium. Superposition produces interference and stationary waves in strings and organ pipes, while simple harmonic motion describes the oscillation itself and must be distinguished from wave propagation.
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