A stone is dropped at t = 0. A second stone, with twice the mass of the first, is dropped from the same point at t = 116 ms.

(a) How far below the release point is the center of mass of the two stones at t = 410 ms? (Neither stone has yet reached the ground.)

_____m

(b) How fast is the center of mass of the two-stone system moving at that time?

_____ m/s