Question

The surface temperature of Pluto is about 45 K. At what wavelength is the peak radiation emitted from Pluto? http://prntscr.com/3oj244

Pluto is not a luminous body. Therefore, it does not emit radiation.
approximately 550 nm
approximately 64,444 nm
approximately 155 nm

Answer 1

The blackbody curve for a star named Beta is shown below. The most intense radiation for this star occurs in what spectral band? http://prntscr.com/3oj930
gamma rays
ultraviolet
visible
infrared

Answer 2

Select all that apply.
The spectrum of Star X is compared to a reference hydrogen spectrum. What can be concluded about Star X?
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Star X is showing radial motion.
Star X is moving toward the Earth.
Star X is moving away from the Earth.
Star X may be moving, but its motion is not radial.

Answer 3

Select all that apply.
The spectrum of Star Y is compared to a reference hydrogen spectrum. What can be concluded about Star Y?
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Star Y is showing radial motion
Star Y is moving toward the Earth
Star Y is moving away from the Earth
Star Y is showing transverse motion

Answer 4

For the black body radiation questions, you can just use Wein's Law:
\[\lambda_\max T = 2.8977721×10^{−3} m K\]Units are meters Kelvin, not millikelvin.

Answer 5

For the spectra questions, just think about the doppler effect. If the source is moving toward you, what happens to the wavelength of the light?