The earth has a mass me = 5.98 · 1024 kg and the moon has a mass mm = 7.36 · 1022 kg. the distance from the center of the earth to the center of the moon is r = 3.82 · 105 km. what is the gravitational force between the earth and moon?

2 x 10^20 N

Explanation:

Me = 5.98 x 10^24 kg

Mm = 7.36 x 10^22 kg

r = 3.82 x 10^5 km = 3.82 x 10^8 m

The gravitational force between earth and moon is

F = G Me x Mm / r^2

F = (6.67 x 10^-11 x  5.98 x 10^24 x 7.36 x 10^22) / (3.82 x 10^8 x 3.82 x 10^8)

F = 2 x 10^20 N

snell's law

refractve index = sin incidence / sin refraction