You would use the 21-cm radio emission line to map out ____________

a. the interstellar medium b. molecular clouds
c. atomic hydrogen clouds d. All of the other choices are correct.


c

Physics & Space Science

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Wien's Law: What are the wavelength and the corresponding photon energy (in electron-volts) of the primary light emitted by an ideal blackbody at each of the following temperatures? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ? s, 1 eV = 1.60 × 10-19 J, and the constant in Wein's law is 0.00290 m ? K) (a) 400°C?(b) 800°C?(c) 1200°C?

What will be an ideal response?

Physics & Space Science

Discuss why the new theory, called quantum mechanics, was so successful

What will be an ideal response?

Physics & Space Science

Motor 1 does 30 J of work in 10 s, motor 2 does 2 J of work in 5 s, motor 3 does 7 J of work in 2 s, and motor 4 does 7 J of work in 3 s. List the motors in order of highest power produced to lowest power produced

a. 2, 4, 1, 3 c. 1, 3, 4, 2 b. 3, 4, 1, 2 d. 3, 1, 4, 2

Physics & Space Science

Estimate the maximum heat flux obtainable with nucleate pool boiling on a clean surface for (a) water at 100 kPa on brass, (b) water at 1 MPa on brass.

GIVEN
? Nucleate pool boiling on a clean surface
FIND
? The maximum heat flux obtainable for
(a) water at 1 atm on brass; and
(b) water at 10 atm on brass
ASSUMPTIONS
? Water is at saturation temperature
PROPERTIES AND CONSTANTS
From Appendix 2, Table 13, for water from Table 9.2 for surface tension

Physics & Space Science