Which type of nebulaeare twisted and distorted clouds of gas and dust dense enough to obstruct the view of the more distant stars?
a. emission nebulae
b. H I
c. reflection nebulae
d. dark nebulae
e. spectral type B6
d
You might also like to view...
The photo shows a galaxy known as Arp 220, and the inset shows this galaxy's spectrum. What can you infer?
A) Most of the light from this galaxy is infrared, indicating active star formation. B) Most of the light from this galaxy is visible light, and it comes from an active galactic nucleus. C) The broad peak is a spectral line indicating the presence of massive amounts of hydrogen gas. D) The spectrum peaks in the infrared, indicating that this galaxy has a huge redshift and must be far away.
If a 3-meter diameter telescope is doubled in size, then its new light collecting power would
A. double. B. increase by a factor of four. C. reduce by half. D. not change.
The components of polyester are _________toxic than epoxy.
Fill in the blank(s) with the appropriate word(s).
The first of two identical boxes of mass m is sitting on level ground. The second box is sitting on a ramp that makes an angle with the ground. When a force of magnitude F is applied to each box in a direction parallel to the surface it is on, upwards on the box on the ramp, neither box moves. Which statement comparing the friction force on the box on the level, Fs,L, to the friction force on the box on the ramp, Fs,R, is correct?
A. Fs,R = Fs,L. B. Fs,R>Fs,L. C. Fs,R