   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.
1 It is much easier to begin a good bedtime routine when your baby is young than to try and change poor sleep routines when you have a toddler or preschooler who still isn't sleeping well.  Do make your bedtime routine age-appropriate. Your child's bedtime routine will change over time. For example, while it is expected for a newborn or younger infant to fall asleep nursing or drinking a bottle of formula, you can try and start putting your baby down while he is drowsy but still awake once he is four or five months old.