A space probe 2.0 * 1010 m from a star measures the total intensity of electromagnetic radiation from the star to be 5.0 * 103 W>m2. If the star radiates uniformly in all directions, what is its total average power output

P = 1.0 10¹⁴ W

Explanation:

Radiation intensity is the power radiated by unit area,

I = P / A

As the star radiates uniformly, the radiation expands into a sphere, the area of this sphere is

A = 4π R²

Let's replace

P = I (4π R²)

Let's calculate the power

P = 5.0 10³ 2.0 10¹⁰

P = 1.0 10¹⁴ W

This is the power radiated by the star