Which of the following is most like the rotation of stars in the disk of the Milky Way?
A)a DVD in a player
B)the planets in our solar system
C)cars moving at a constant speed on a circular race track
D)the hands of an analog clock
E)the tire of a car moving

Question

Quizplus · Accepted Answer

The rotation of stars in the disk of the Milky Way is like cars moving at a constant speed on a circular race track. Both involve objects moving in a circular path at a constant speed, with the outer objects moving faster than the inner objects. The other options do not accurately represent the rotation of stars in the Milky Way. Cars moving at a constant speed on a circular race track are most like the rotation of stars in the disk of the Milky Way. Both involve objects moving in a circle at a constant speed, without changing direction or accelerating. The other options (A, B, D, and E) do not accurately capture the rotational motion of stars in the Milky Way. A DVD in a player spins, but does not move in a circular path; the planets in our solar system orbit the Sun, but are not part of the Milky Way's disk; the hands of an analog clock move in a circle, but do not involve many separate objects rotating together; and the tire of a car moving may spin, but does not move in a circular path relative to other objects.

Which of the Following Is Most Like the Rotation of Stars