With what speed should a galaxy move outward with respect to Earth so that the sodium-$D$ line at wavelength $5890 \ \mathring{A}$ is observed at $5896 \ \mathring{A}$? (in $\text{km/s}$)

If a star is moving towards the Earth,then the spectral lines are shifted towards:

Light from the constellation Virgo is observed to increase in wavelength by $0.4\%$. With respect to Earth,the constellation is:

The Doppler effect in sound,in addition to the relative velocity between the source and the observer,also depends on the individual motion of the source and the observer relative to the medium. However,the Doppler effect in light depends only on the relative velocity between the source and the observer. The reason for this is:

If the shift of wavelength of light emitted by a star is towards the violet end of the spectrum,then this shows that the star is

Hubble showed that the universe as a whole is expanding and the distant stars are receding from us. The spectral line from a star,when compared with the corresponding line from a stationary source,will then show: