Part of an automatic transmission consists of a fixed ring gear R, three equal planet gears P,

Question:

Part of an automatic transmission consists of a fixed ring gear R, three equal planet gears P, the sun gear S, and the planet carrier C, which is shaded. If the sun gear is rotating with angular velocity ω_s. determine the angular velocity ω_c of the planet carrier. Note that C is pin-connected to the center of each of the planet gears.