Planets' and Sun's mean angular velocity

In summary, the Earth's rotation speed in inertial space is (7.2921150 ± 0.0000001) ×10−5 radians per SI second and rotates more than 360° relative to the fixed stars in one solar day. To calculate the mean angular velocity for any other planet in the Solar system, one can take the inverse of the rotation period and multiply it by 2 pi to get the value in rad/s. The given data for the mean angular velocity in rad/s for various planets and the Sun can be verified in books or papers.
  • #1
FutureScience
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From "[URL Wikipedia - Earth's rotation[/URL]

The angular speed of Earth's rotation in inertial space is (7.2921150 ± 0.0000001) ×10−5 radians per SI second (mean solar second).[11] Multiplying by (180°/π radians)×(86,400 seconds/mean solar day) yields 360.9856°/mean solar day, indicating that Earth rotates more than 360° relative to the fixed stars in one solar day.

If I want to know the mean angular velocity for any other planet of the Solar system and for the Sun itself, should I take the rotation period for each object and do the inverse in order to get the angular velocity in rad/s?

Here there is a list of rotation periods for the above objects:

http://en.wikipedia.org/wiki/Rotation_period
 
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  • #2
FutureScience said:
From "[URL Wikipedia - Earth's rotation[/URL]

The angular speed of Earth's rotation in inertial space is (7.2921150 ± 0.0000001) ×10−5 radians per SI second (mean solar second).[11] Multiplying by (180°/π radians)×(86,400 seconds/mean solar day) yields 360.9856°/mean solar day, indicating that Earth rotates more than 360° relative to the fixed stars in one solar day.

If I want to know the mean angular velocity for any other planet of the Solar system and for the Sun itself, should I take the rotation period for each object and do the inverse in order to get the angular velocity in rad/s?

Taking the inverse of the rotation period will give you rotations per sec. Since a full rotation consists of 2 pi radians, you will have to multiple this by 2 pi to get rad/s.
 
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  • #3
The data that I've about the mean angular velocity, all in rad/s are:

Earth = 7.292115053925690e-05,

Jupiter = 1.773408215404907e-04,

Mars = 7.088218127178316e-05,

Mercury = 1.240013441242619e-06,

Moon = 2.661699538941653e-06,

Neptune = 1.083382527619075e-04,

Pluto = -1.295641039282477e-05

Saturn = 1.636246173744684e-04,

Sun = 2.865329607243705e-06,

Uranus = -1.041365902144588e-04

For the Sun and for the bigger planets I've taken the equatiorial/deep interior value for the roation period.

Could anyone please crosscheck them or verify those number in some book or papers?

Thanks in advance!
 

FAQ: Planets' and Sun's mean angular velocity

What is mean angular velocity?

Mean angular velocity refers to the average rate at which a planet or the Sun rotates around its axis. It is measured in degrees per unit time, such as degrees per day.

How is mean angular velocity calculated?

Mean angular velocity is calculated by dividing the total angular displacement of a planet or the Sun by the time it takes to complete one rotation. This can be expressed as: mean angular velocity = (total angular displacement) / (time taken).

Why is mean angular velocity important?

Mean angular velocity is important because it helps us understand how fast a planet or the Sun is rotating. This information can provide insight into the planet's or Sun's structure, atmosphere, and other important characteristics.

Does mean angular velocity change for different planets?

Yes, mean angular velocity can vary for different planets. This is because each planet has a different size, mass, and distance from the Sun, which can affect its rate of rotation. For example, smaller planets tend to rotate faster than larger planets.

How does the Sun's mean angular velocity compare to that of the planets?

The Sun's mean angular velocity is much slower compared to that of the planets. The Sun's rotation period is about 27 days, while the planets have rotation periods that range from a few hours to several days. This is because the Sun is much larger and has a stronger gravitational pull, causing it to rotate more slowly.

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