   A heavier plane has more momentum (when thrown at the same speed),  but it's also got more downward force acting on it. If it has the  same wing area, though, it has the same lift, so it drops more  quickly than a light plane (objects fall at the same speed only in  the absence of air resistance).
By 2 months, baby's bedtime should be between 6:00-8:00pm and should occur about 1 hour after the last nap ends. 3 months: babies this age should be on a solid 4 nap schedule with the last nap of the day ending by 5:00pm.
Second Month Baby Milestones: Sleep. Your babyâs sleep patterns are evolving, but at two months, they still arenât fully established. At this age, babies sleep 15 to 16 hours a day. But those hours are sporadic, and they usually arenât ready to sleep through the night.