How many rotations does the earth make in an average year of 365 1/4 days?

Question

Rotation of the earth causes night and day, but it is not 365 1/4 rotations! Clue: revolultion.

Answer 1

366 1/4

If you measure according to the "fixed star", one rotation takes 86,164.1 seconds.

While we turn around once, we will have move a bit on our orbit around the sun (almost one degree), so that the earth has to turn 361 degrees (relative to the stars) to make one complete turn relative to the sun. That takes, on average, 86,400 seconds (exactly 24 hours).

One year is 365.25 = 31,557,600 seconds

31,557,600 seconds divided by 86,164.1 second per turn =
366.25 turns.

Answer 2

Earth Rotations

Answer 3

Who is giving the thumbs down to good answers?

There are about 366.25 sidereal days in a solar year. One revolution of the Earth is lost by the fact that we orbit the sun. Think of it this way: If Earth didn't rotate, there would be one solar day per year, because as Earth moved around the sun, different sides of it would be illuminated. If it rotated once per year then it wouldn't have changing day/night, one side would always face the sun.

Generally speaking, the number of solar days a planet experiences is equal to the number of full rotations it makes in its year minus 1. If it rotates in the opposite direction of it's orbit, you can say the number of rotations is negative, so the equation still works.

0 rotations in a year -1 = -1 solar days, which is just one solar day where the sun rises in the west.

1 rotation in a year -1 = 0 solar days

366.25 rotations in a year - 1 = 365.25 solar days

-366.25 rotations in a year -1 = -367.25 solar days (sun would rise in the west because days is negative).

Answer 4

revolution - 365 1/4 days
rotation - 24 * 365 1/4

Answer 5

The quantity 365.26 has some validity, yet in an imprecise way. The year it quite is sensible for the calendar is one that keeps the seasons in sync -- for occasion, the vernal equinox ought to happen in regards to the comparable time each year and should not choose the flow over the centuries. that's named a tropical year (defined because of the fact the era between vernal equinoxes): tropical year = 365.242190 days the suited calendar may well be arranged so we've an subject-freed from 365.242190 days in a year. The Gregorian calendar (that we use) has an subject-freed from 365.2425 days in a year, so this is totally close, whether it is going to choose the flow with the aid of at some point each 3326 years. (The previous Soviet Union quite got here up with a calendar that become somewhat extra effective than the Gregorian, so as that they might say they had a extra effective calendar than the U.S.) the suited calendar does not be designed to compromise with the different variety of year; the only purpose is to examine the tropical year to boot as achieveable. the only compromise is that it would be undemanding sufficient for persons to appreciate it. yet astronomers additionally communicate approximately numerous different sorts of years. for occasion, a "sidereal year" is the time it takes for the earth and sunlight to line up lower back with the comparable spot on the celestial sphere. An "anomalistic year" is defined because of the fact the era between perihelions (i.e., whilst the earth is closest to the sunlight). They fluctuate from a tropical year because of the fact of teen perturbations. (an suited 2-physique equipment does not have those categories of years.) those years have right here lengths: sidereal year = 365.256363 days anomalistic year = 365.259635 days those numbers, whilst rounded, are the comparable because of the fact the quantity given with the aid of giantpandadog; yet they don't look to be the numbers you prefer to apply to create a civil calendar. one extra merchandise: Take the version between a tropical year and a sidereal year, and divide it into the size of a tropical year. the end result's approximately 25800; that's how some years it is going to take earlier the style of tropical and sidereal years fluctuate with the aid of one. look conventional? that's the era of the precession of the equinoxes -- i.e., how long it takes for the earth's pole to end one turn because it wobbles in regards to the axis of the ecliptic, and how long it takes between eras whilst Polaris is the north megastar.

Answer 6

You're right. It takes 23 hours 56 minutes, not 24 hours, for the Earth to complete a revolution so it rotates 366.25 times in a year.

Answer 7

Relative to the stars it rotates on its axis 366 1/4 times and also revolves around the Sun once.

Answer 8

366.2422 rotations to make 365.2422 seasonal days, 366.25 rotations to make 365.25 Julian calendar days, 366.2425 rotations to make 365.2425 Gregorian calendar days, 366.25636 rotations to make 365.25636 days in a sidereal year. All these answers are correct relative to geometric formula (note the fractional remains the same in ratio of a full circle).

Answer 9

The sidereal year is the time taken for the Sun to return to the same position with respect to the stars of the celestial sphere. It is the orbital period of Earth, equal to 365.25636042 mean solar days - 365.25636042 earth rotations or sidereal days.

A tropical year (solar year) is the length of time the Sun, as seen from the Earth, takes to return to the same position along the ecliptic. A tropical year is shorter than a sidereal year (in 2000, the difference was 20.409 minutes).

The difference is caused by the precession of the equinoxes. One sidereal year is roughly equal to 1 + 1/26000 or 1.000039 tropical years.

Answer 10

well, then its 730 LOL!!!