Answer:
Doppler shift of the starlight
Explanation:
To predict the movement of a star, we compare the spectra of elements found in star (H, He Na etc.), first spectra which are obtained from star and second spectra from laboratory. If spectral lines of the spectra obtained from star, are shifting towards red end (called red shift) then star is going away from earth and if shifting is towards blue (called blue shift), then star is approaching the earth. This is Doppler's shift.
Answer:
The crest to trough distance = 8 m
Explanation:
Given that,
The amplitude of a particular wave is 4.0 m.
We need to find the crest to trough distance.
We know that,
Amplitude = The distance from the base line to the crest or the the distance from the baseline to the trough.
It means,
Distance from crest to trough = 2(Amplitude)
= 2(4)
= 8 m
Hence, the crest to trough distance is equal to 8 m.
Answer:
it's D. Make the column wider
Explanation: