(Solved): (5pts) Neptune has an orbital period of 165 yr and a semi-major axis of 30 AU . If our solar system ...

(5pts) Neptune has an orbital period of 165 yr and a semi-major axis of 30 AU . If our solar system formed from a cloud of gas with a temperature of 10 K , a mass of ?1 solar mass, and a composition of mostly molecular hydrogen, what was the initial rotation period of the birth cloud?