Physics, 08.03.2021 20:10 martinjohnsond079
Suppose that you'd like to find out if a distant star is moving relative to the earth. The star is much too far away to detect any change in its brightness as it moves toward or away from the earth. Instead we can use the Doppler effect to determine its relative speed. For this problem we are going to look at the spectral lines from hydrogen, specifically the one with a wavelength of 656.46 nm.
The hydrogen atoms in a star are also moving at high velocity because of the random motions caused by their high temperature. As a result, each atom is Doppler shifted a little bit differently, leading to a finite width of each spectral line, such as the 656.46-nm line we were just discussing. For a star like our sun, this leads to a finite width of the spectral lines of roughly Δλ=0.04nm.
If our instruments can only resolve to this accuracy, what is the lowest speed V, greater than 0, that we can measure a star to be moving?
Answers: 2
Physics, 22.06.2019 09:30, ayeheavymetal
The graph represents the distance a car travels over time while on the highway. which statement about the car's trip is accurate? a) the car does not move over time. b) the car travels at a constant velocity. c) the car's velocity increases constantly over time. d) the car's velocity decreases constantly over time.
Answers: 1
Physics, 22.06.2019 13:40, sbudlove2838
What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th
Answers: 1
Physics, 22.06.2019 17:00, gtamods402
How many meters will a car travel if its speed is 45 m/s in an interval of 11 seconds? question 2 options: a) 450 meters b) 495 meters c) 4.09 meters d) 498 meters
Answers: 2
Suppose that you'd like to find out if a distant star is moving relative to the earth. The star is m...
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