Question

In a solar system far far away, the sun's intensity is 100 W/m2 for a planet located a distance R away. What is the sun's intensity for a planet located at a distance 5 R from the Sun

Answer 1

Answer:

The sun's intensity for a planet located at a distance 5 R from the Sun is 4 W/m²

Explanation:

The intensity of Sun located at a distance of R away is $100\ W/m^2$.

We need to find the sun's intensity for a planet located at a distance 5 R from the Sun. Intensity is given by :

$I\propto \dfrac{1}{r^2}$

So,

$\dfrac{I_1}{I_2}=(\dfrac{r_2}{r_1})^2$

Here, I₁ = 100 W/m² and r₁ = R and r₂ = 5R

$I_2=\dfrac{I_1r_1^2}{r_2^2}$

$I_2=\dfrac{100(R^2)}{(5R)^2}\\\\I_2=\dfrac{100}{25}\\\\I_2=4\ W/m^2$

So, the sun's intensity for a planet located at a distance 5 R from the Sun is 4 W/m².