The Sun emits light waves in all directions.When this light reaches the Earth,its intensity is 1350 W/m².What is its intensity when it reaches Mars? The distance from the Sun to the Earth is 1.50 * 10¹¹ m and the distance from the Sun to Mars is 2.28 * 10¹¹m. A)584 W/m² B)888 W/m² C)2050 W/m² D)3120 W/m²

Question

Quizplus · Accepted Answer

The intensity of light from a point source (like the Sun) decreases with the square of the distance from the source. This is described by the inverse square law: $I = \frac{P}{4\pi r^2}$, where $I$ is the intensity, $P$ is the power of the source, and $r$ is the distance from the source. Since the intensity at Earth is given as 1350 W/m^2 at a distance of $1.50 \times 10^{11} m$, and the distance to Mars is $2.28 \times 10^{11} m$, we can use the ratio of the squares of the distances to find the intensity at Mars: $\frac{I_{Earth}}{I_{Mars}} = \frac{(2.28)^2}{(1.50)^2}$. Solving for $I_{Mars}$ gives an intensity of approximately 584 W/m^2.

The Sun Emits Light Waves in All Directions