38
QuizMultiple Choice

N/A — Exam

Question 38 • Physics

Which statements describe the motion of a planet according to Kepler’s second law? Choose two correct answers.

Answer
A
The speed of a planet is constant as it moves in its orbit.
B
A planet’s orbit is a circle centered on the Sun.
C
A planet travels the same distance along its orbit in equal units of time.
D
A planet sweeps out an equal area in equal units of time.
E
The speed of a planet varies as it moves in its orbit.
F
A planet’s orbit is an ellipse with the Sun at one focus.

Explanation

Kepler’s second law says that a line from a planet to the Sun sweeps out equal areas during equal time intervals. Because the planet covers a larger distance when it is nearer the Sun and a smaller distance when farther away, its speed varies along its orbit. Thus the correct statements are that the planet’s speed varies and that it sweeps out equal areas in equal times.

AI-written and checked against the verified answer.

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