Given that the distance to the Moon is 384000 km, and taking the Moon's orbit around Earth to be circular, estimate the speed (in kilometers per second) at which the Moon orbits Earth.

The speed at which moon orbits earth, is found to be 27.92 km/s

Explanation:

Considering the orbit of moon to be circular, with earth as center and the orbit of moon around earth being the circumference, here we have:

radius = r = 384000 km

since the moon completes one revolution around earth in one day:

angular speed = ω = (2π rad/24hr) (1 hr/60 min) (1 min/60 sec)

ω = 7.27 x 10^ (-5) rad/sec

Now for linear speed of moon:

V = rω = (384000 km) (7.27 x 10^ (-5) rad/sec)

V = 27.92 km/s