Sirius is 22 times more luminous that the Sun, and Polaris is 2350 times more luminous that the Sun. Sirius appears 23 times brighter than Polaris. Polaris is ______ times farther away than Sirius.

Respuesta :

Answer:

Polaris is approximately 4.796 times farther away than Sirius.

Explanation:

According to the inverse-square law, widely used in wave phenomena, the luminosity, a form of intensity of electromagnetic webs, is inversely proportional to the square of distance. In other words, we get the following definition:

[tex]I \propto \frac{1}{r^{2}}[/tex]

[tex]I = \frac{k}{r^{2}}[/tex] (Eq. 1)

Where:

[tex]k[/tex] - Proportionality ratio, measured in watts.

[tex]r[/tex] - Distance from the center of the star, measured in meters.

[tex]I[/tex] - Luminosity of the star, measured in watts per square meter.

Then, we eliminate the proportionality ratio by constructing the following relationship:

[tex]I_{S}\cdot r_{S}^{2} = I_{P}\cdot r_{P}^{2}[/tex] (Eq. 2)

Where:

[tex]I_{S}[/tex], [tex]I_{P}[/tex] - Intensities of Sirius and Polaris, measured in watts per square meter.

[tex]r_{S}[/tex], [tex]r_{P}[/tex] - Distances from centers of Sirius and Polaris, measured in meters.

After some algebraic handling, we get that:

[tex]\frac{r_{P}}{r_{S}} = \sqrt{\frac{I_{S}}{I_{P}} }[/tex]

If we know that [tex]\frac{I_{S}}{I_{P}} = 23[/tex], then the distance ratio of Polaris to Sirius is:

[tex]\frac{r_{P}}{r_{S}} =\sqrt{23}[/tex]

[tex]\frac{r_{P}}{r_{S}} \approx 4.796[/tex]

In a nutshell, Polaris is approximately 4.796 times farther away than Sirius.