Which statement describes Kepler’s third law of orbital motion
Kepler's third law of orbital motion states that the square of the orbital period of a planet is directly proportional to the cube of its average distance from the sun.
Kepler's third law of orbital motion, also known as the harmonic law, states that the square of the period (T) of a planet's orbit is directly proportional to the cube of its average distance (r) from the sun. Mathematically, it can be expressed as T^2 = k*r^3, where k is a constant value for a given system. This law indicates that the farther a planet is from the sun, the longer its orbital period will be.
Kepler's third law of orbital motion states that the square of the orbital period of a planet is directly proportional to the cube of its semi-major axis. In other words, the time it takes for a planet to complete one orbit around the sun is related to the size of its orbit.
To understand this law, we need to know a few key terms:
1. Orbital period: The time it takes for a planet to complete one full orbit around its star.
2. Semi-major axis: A measure of the size of an elliptical orbit, which represents half of the longest diameter across the ellipse.
Now, let's see how to calculate the orbital period using Kepler's third law:
1. Determine the semi-major axis (a) of the planet's orbit. This can be obtained from astronomical observations or given as part of the problem.
2. Square the orbital period (T) of the planet. This can be measured or given as well.
3. Cube the semi-major axis (a) of the planet's orbit.
4. Divide the squared orbital period by the cubed semi-major axis.
The resulting value will be a constant, which is the same for all planets orbiting the same star. This constant is known as the "universal gravitational constant" (G) times the mass of the central star (M).
To summarize, Kepler's third law states that the square of the orbital period (T) divided by the cube of the semi-major axis (a) is equal to a constant value. This relationship holds true for any planet orbiting a star.