Red-shift (physics Only) (GCSE Physics)

Which of the following would produce a blueshift rather than a redshift for a star’s spectral lines?

A galaxy has redshift z = 0.5. Which is true compared to small-z Doppler approximation?

Which of these is NOT a cause of observed redshift of light from astronomical objects?

Which of the following best describes what a positive redshift (z > 0) of a galaxy’s light indicates?

When interpreting galaxy redshifts, why must astronomers consider peculiar velocity (local motion) as well as cosmological recession?

Why do the dark lines in the spectrum of a distant galaxy match the same pattern of lines in the Sun’s spectrum even though the lines are shifted?

The dimensionless redshift z is defined as (observed wavelength - rest wavelength) divided by rest wavelength. Which algebraic expression matches that definition?

Why do astronomers compare the pattern of dark absorption lines in a star or galaxy spectrum to laboratory spectra of known elements?

Which of these is a limitation when using redshift to determine very large cosmological distances?

Which discovery about spectral line patterns in distant galaxies (same pattern but shifted) was crucial to concluding galaxies contain the same chemical elements as Earth?

A spectral absorption line has rest wavelength 500.0 nm. In a galaxy it is observed at 505.0 nm. What is the redshift z?