How would you calculate the speed at which the moon revolves around the earth in m/s?

1 Answer

speed equals orbital radius times the orbital angular speed


The moon is 384,000 km away from the Earth. It revolves around the earth in 27.3 days.

it's speed is : #v = r omega = r (2pi)/T=\frac{2\pi.r}{T}#,

where #T# is the lunar orbital period, and #r# the orbital radius of moon (the moon follows an ellipse but the eccentricity is small enough that you can treat it as a circle.)

This gives you,

#v = (384,000 \quad km)\times (2pi)/((27.3\quad days)\times (86400\quad s/(day)))#
# = 1.023 \quad(km)/s#