2. Kepler determined that planets change their speed as they travel around * the sun. This happens due to all of the following
A). The sun's gravity makes the planets slow as they get closer
B). The sun's gravity pulls against the planet's inertia in some places
C). The sun's gravity pulls with the planet's inertia in some places
D). The planets' orbits are elliptical
A). The sun's gravity makes the planets slow as they get closer
B). The sun's gravity pulls against the planet's inertia in some places
D). The planets' orbits are elliptical
The correct answer is:
A) The sun's gravity makes the planets slow as they get closer
B) The sun's gravity pulls against the planet's inertia in some places
C) The sun's gravity pulls with the planet's inertia in some places
D) The planets' orbits are elliptical
The correct answer is A, B, and D.
To determine the correct answer, let's first understand Kepler's laws of planetary motion. Kepler was a German astronomer who made important discoveries about how planets move. His three laws of planetary motion describe the motion of planets around the Sun.
Kepler's first law states that the orbit of a planet around the Sun is an ellipse, with the Sun located at one of the focal points of the ellipse. This means that option D is correct, as the planets' orbits are indeed elliptical.
Kepler's second law, also known as the law of equal areas, states that a line segment joining a planet and the Sun will sweep out equal areas in equal intervals of time. This implies that a planet speeds up as it gets closer to the Sun and slows down as it moves away from the Sun. So, option A is correct because the Sun's gravity makes the planets slow down as they get closer.
Finally, Kepler's third law, also known as the harmonic law, establishes a relationship between a planet's orbital period and its distance from the Sun. It shows that the further a planet is from the Sun, the longer it takes to complete its orbit. This law doesn't directly relate to the question, but it provides additional context about planetary motion.
Option B is incorrect because while the Sun's gravity does pull against the planet's inertia in some places, this is not the reason for the change in speed of the planets around the Sun.
Option C is incorrect; the Sun's gravity does not pull with the planet's inertia in some places. The change in speed of the planets is primarily due to the varying gravitational force exerted by the Sun on the planets as they move along their elliptical orbits.
In summary, Kepler determined that planets change their speed as they travel around the Sun due to the Sun's gravity making the planets slow as they get closer (option A) and the planets' orbits being elliptical (option D).