What is the distance from the sun in the astronomical unit, that is, what is the average mean distance of the Earth?
149,598,000 kilometers
Understanding Earth's Distance from the Sun: Astronomical Units
The question asks about the distance from the Sun, specifically focusing on the average mean distance of the Earth, which is defined as one astronomical unit. This is a fundamental concept in astronomy used to measure distances within our solar system.
What is an Astronomical Unit (AU)?
An Astronomical Unit (AU) is a unit of length, roughly the distance from Earth to the Sun. It is officially defined as 149,597,870,700 meters, or approximately \(149,598,000\) kilometers.
The AU is used because distances in the solar system are vast. Using kilometers or miles would result in very large numbers that are cumbersome to work with. Using AUs makes these distances more manageable. For example, Jupiter is about 5.2 AU from the Sun.
Earth's Average Distance from the Sun in Kilometers
The Earth's orbit around the Sun is not a perfect circle; it's slightly elliptical. This means the Earth's distance from the Sun varies throughout the year. The average of this varying distance is what defines the Astronomical Unit.
The average distance of the Earth from the Sun is approximately \(149,598,000\) kilometers.
Analyzing the Options
Let's look at the given options for the distance in kilometers:
- Option 1: \(598,149,000\) kilometers
- Option 2: \(149,598,000\) kilometers
- Option 3: \(1,149,598,000\) kilometers
- Option 4: \(128,983,000\) kilometers
We are looking for the average distance of the Earth from the Sun, which is the definition of 1 AU, approximately \(149,598,000\) kilometers.
Comparing this value to the options, we see that Option 2 matches the approximate average distance of the Earth from the Sun.
Therefore, the distance from the Sun in the astronomical unit, which is the average mean distance of the Earth, is approximately \(149,598,000\) kilometers.
Revision Table: Key Astronomical Distances
| Term | Definition / Value | Use |
|---|---|---|
| Astronomical Unit (AU) | Average distance between Earth and Sun (~ \(149.6 \times 10^6\) km) | Measuring distances within solar system |
| Light-Year (ly) | Distance light travels in one year (~ \(9.46 \times 10^{12}\) km) | Measuring distances to stars and galaxies |
| Parsec (pc) | Distance at which 1 AU subtends an angle of 1 arcsecond (~ 3.26 ly or \(3.08 \times 10^{13}\) km) | Measuring distances to stars and galaxies (often used by professionals) |
Additional Information on Earth's Orbit and AU
The Earth's orbit is an ellipse. The point in the orbit closest to the Sun is called perihelion, and the point farthest from the Sun is called aphelion.
- Perihelion: Approximately \(147.1 \times 10^6\) km (0.983 AU)
- Aphelion: Approximately \(152.1 \times 10^6\) km (1.017 AU)
The Astronomical Unit is defined as the semi-major axis of a hypothetical, unperturbed Earth orbit, which is very close to the average of the perihelion and aphelion distances. The precise value is internationally standardized.
Important Questions from Units, Dimensions and Measurements
According to Newton's second law of motion, force ($F$) is defined as the product of mass ($m$) and acceleration ($a$), i.e., $F=ma$. If an object with a mass of $1 \text{ kg}$ experiences an acceleration of $1 \text{ m/s}^2$, what is the standard SI unit used to quantify this force?
kg m/sec is the unit of
Which of the following instruments is used to measure the radius of wires?
The dimension of linear momentum is identical to that of which of the following expressions?
Which system has been accepted as the international standards of measurement with seven base units for length, mass, time, temperature, electric current, luminous intensity and amount of substance?
I. Metric system
II. Imperial or British system
