Why are galaxies in the blue cloud blue?
A) They contain hot, young stars that signify active star formation.
B) They are moving slower than stars in the red cloud.
C) They contain lots of dust that cause the bluish color.
D) They contain cold, dying stars that are fading to black.
A
You might also like to view...
Calculate the percentage composition by mass (to the nearest 0.1) of each element in sodium sulfide, Na2S
Equal currents of magnitude I travel out of the page in wire M and into the page in wire N. Eight directions are indicated by letters A through H
The direction of the magnetic field at point P is
a.
A.
b.
B.
c.
C.
d.
D.
e.
E.
Gravitational lensing is the process by which
A) a massive object magnifies and distorts the light from an object behind it B) the wavelengths of light from a star are shifted as it moves about its center of mass C) a planet passes in front of its parent star and blocks part of its light D) a massive object accelerates another object that passes close to it
A longitudinal wave travels on a slinky or any long spring. The wave is represented by the equation z(z, t) = 1.2 cm cos(1800 rad/s t + 60
z). What is the wave vector of the wave?
A. 60 
in the + z direction
B. 60 in the - z direction
C. 60 in the + x direction
D. 60 in the - x direction