Question

Which statement best describes what keeps galaxies together?

A. The stars and other bodies of a galaxy are held together because of their
motion and the gravitational pull toward the outer regions of the
galaxy.

B. The stars and other bodies of a galaxy are held together because of mutual
gravitational attraction to one another and the gravitational pull toward
matter in the center of the galaxy.

C. The stars and other bodies of a galaxy are held together because of their
small size and the gravitational pull of other galaxies.

D. The stars and other bodies of a galaxy are held together because of the
gravitational pull of our sun and the gravitational pull of the outer regions of
the galaxy.

Answer 1

Answer: The stars and other bodies of a galaxy are held together because of mutual

gravitational attraction to one another and the gravitational pull toward

matter in the center of the galaxy.

A. is incorrect because motion is not a factor in the gravitational attraction of objects within a galaxy.

B. is correct because the mutual gravitational attraction of the stars and other bodies in a galaxy, as well as the gravitational pull toward the matter in the center of the galaxy, are the main factors that keep a galaxy together.

C. is incorrect because the size of the objects in a galaxy does not affect their gravitational attraction to one another.

D. is incorrect because the gravitational pull of our sun is not a significant factor in the gravitational attraction of objects within a galaxy.