Explanation:
Radius of moon around earth, r = 3.84 × 10⁸ m
Circumference of orbit = 2πr = 2 x 3.14 x 3.84 × 10⁸
Circumference of orbit = 2.41 x 10⁹ m
Time taken, t = 27.3 days = 27.3 x 24 x 60 x 60 = 2358720 seconds
We have
Circumference of orbit = Speed of moon x Time taken
2.41 x 10⁹ = Speed of moon x 2358720
Speed of moon = 1021.74 m/s
The average speed of the moon around the earth is 1021.74 m/s