Chapter 7, Problem 2RQ

In hydrogen, the transition from level 2 to level 1 has a rest wavelength of 121.6 nm. Find the speed for a star in which this line appears at wavelength 120.5 mm. What about at 122.4 nm? Express your answer to three significant figures and include the appropriate units.

ten thousand: 10 ✕ 103 = 104 one hundred thousand: 100 ✕ 103 = 102 ✕ 103 = 105 How do we write ten million?   10 ✕ 106 = 10   How do we write one hundred billion? 10

What would be the gamma factor for a spacecraft traveling at 7,800 m/s?  a 0.85  b 1.0  c 1.1  d 1.8   A new version of the starship rocket has a length of 50 m. It is designed to travel at 0.4 c. What would be the length of the craft traveling at that speed?  a 46 m  b 49 m  c 50 m  d 53 m

A star has an element in its atmosphere that normally emits a line of frequency fs = 7.5 x 10^14 vib/s. If astronomers measure the frequency of this line to be fo = 7.7 x 10^14 vib/s, then how fast are the Earth and this star traveling relative to each other? Remember that the correct equation for the speed v is given by v = [(fo^2 - fs^2) / (fo^2 + fs^2)] c Remember fo^2 means "fo squared."