Why do we think there is a lot of dark matter in clusters of galaxies?
A.) Individual galaxies are moving so fast that they could not be held together by the gravity of visible matter.
B.) We've detected some of it with dark matter telescopes.
C.) Gravitational lensing lets us measure mass even when we can't see it.
D.) A, B, and C.
E.) A and C.
Ans: E.) A and C.
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Moment of Inertia: A triatomic molecule is oriented as follows along the x-axis: mass m is at the origin, mass 2m is at x = a, and, mass 3m is at x = 2a. What is the moment of inertia of this molecule about the y-axis?
A. 2ma2 B. 3ma2 C. 12ma2 D. 14ma2
A pan of water boils on the stove.
C. Consistent D. Inconsistent
When referring to the "mks" system, what does the "m", the "k", and the "s" stand for?
What will be an ideal response?
The apparent path that the Sun traces annually along the celestial sphere is called the
a. ecliptic. b. heliosphere. c. solstice circle. d. celestial prime meridian.