Based on Kepler's observations about planetary motion, what is the relationship between a planet's orbital velocity and its distance from the sun?(1 point)
Distance has no effect on orbital velocity.
Distance has no effect on orbital velocity.
As distance is cut in half, orbital velocity decreases.
As distance is cut in half, orbital velocity decreases.
The greater the distance, the slower the orbital velocity.
The greater the distance, the slower the orbital velocity.
The greater the distance, the greater the orbital velocity.
The greater the distance, the slower the orbital velocity.
The answer is: The greater the distance, the slower the orbital velocity.
The correct answer is:
The greater the distance, the slower the orbital velocity.
To understand why this is the case, we need to look at Kepler's laws of planetary motion. Johannes Kepler, a German astronomer, made observations about the motion of planets around the Sun in the early 17th century. One of his laws, known as Kepler's second law or the law of equal areas, states that a planet sweeps out equal areas in equal time intervals as it orbits the Sun.
To explain this law, we can consider a planet moving in an elliptical orbit around the Sun. The planet moves fastest when it is closest to the Sun (perihelion) and slowest when it is farthest from the Sun (aphelion). This observation is consistent with Kepler's second law.
The reason for this relationship between orbital velocity and distance from the Sun is due to the conservation of angular momentum. The angular momentum of a planet remains constant throughout its orbit as long as no external forces act upon it. Angular momentum is the product of an object's mass, orbital velocity, and distance from the center of mass.
So, when a planet is closer to the Sun, its distance from the center of mass is smaller, which means its orbital velocity must be higher to maintain the same angular momentum. Conversely, when a planet is farther from the Sun, its distance from the center of mass is greater, which means its orbital velocity must be lower to maintain the same angular momentum. This is why the greater the distance from the Sun, the slower the orbital velocity.