1 Hydrogen has a spectral line at wavelength 121.6nm. Suppose you see this line
ID: 2259206 • Letter: 1
Question
1 Hydrogen has a spectral line at wavelength 121.6nm. Suppose you see this line at a wavelength of 120.5nm in Star A, 121.2nm in Star B, 121.9nm in Star C, and 122.9nm in Star D. Which stars are coming toward us? Which are moving away? Which star is moving fastest relative to us? Explain your answers.
.2) How would the equilibrium temperature of the Earth be different if the following were true? Explain your reasoning
a. If the entire surface of the Earth was white
b. IftheEarthwereclosertothesun
c. If the Earth had no atmosphere
d. IftheEarthhadathickeratmospheremadeupofcarbon ?dioxide
Explanation / Answer
The wavelengths of light from approaching objects will shorten, and those from receding objects lengthen.
this is an example of Doppler effect.
the star having less wavelength than spectral line are approching ones and the star having more wavelength than spectral line are receding ones
Approaching stars are A and B,
Receding Stars are C and D,
fastest star will have greatest differnce of wavelength ,
we can see, diff between lamda of D is largest w r t to our spectral line.
hence D is the fastest star.
2)1. If the entire surface of the Earth was white,
the temperature of earth would have been low, as majority of the light falling on the earth would have been reflected. hence the amount of light absorbed would be less, resulting in less temperature.
2. ftheEarthwereclosertothesun ,
The equilibrium temp would have been very high beacause of high intensity of light falling on earth.
3. Atmosphere contains Green house gases, which are responsible for heating of the earth majorly,
hence if If the Earth had no atmosphere,
the temp of earth would have been lowered. also The difference in temperature between the day side and the night side would be more extreme. It'd be normal to see temperature variations of the order of several tens of degrees, maybe up to some 100 degrees.
4. We Know the CO2 is a major green house gas which is responsible for heating of the earth majorly , if Ift he Earth had a thicker atmosphere made up of carbon ?dioxide, ithe temperature would have been raised highly.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.