one of the exercises in my Physics Book, is to calculate the radius of the moon, given the following:
Earth's mass = 5.974e+24 kg
Moon's mass = 7.3483e+22 kg
Moon's average speed = 1023 m/s
Using what you know about Centripetal and Gravitational Force..
Now, I figured that the radius of the moon's orbit, could be calculated with:
r = (moon's mass) * speed^2 / Fc
Fc = Centripetal Force
However, I don't know what the centripetal force of the moon is (in relation to the earth) .. I'm guessing that this is where my (supposed) knowledge of gravity is supposed to come into play.. i.e. Replace the Fc with the Gravitational force between the earth and moon... However, the book doesn't give that value... and surely it can't be calculated without knowing the distance between the earth and the moon (which is the radius of orbit -- which is what we're trying to calculate here!).
Is it possible to calculate this with the info provided? Thanks.