Question

guys,can you solve it??​

Answer 1

Answer:

See below.

Explanation:

First, we calculate the area of moon's surface ( i.e the area of the disc as seen from Earth ). The diameter is 3474 km. Hence, the area is,

$A = \pi r^2 = \pi  (3.474 \times 10^3)^2 = 3.79 \times 10^7  \ (km)^2$

To calculate the solid angle,

$\Omega = \frac{A}{d^2} = \frac{3.79 \times 10^7  \ (km)^2}{ (3.84 \times 10^5)^2 \ (km)^2 } = \frac{3.79}{14.74}\times 10^{-3} = 2.57 \times 10^{-4}$

And that's your answer. See the attached image for reference.