   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.
The experts unanimously agree on the average child's need to nap and on a napping schedule: Newborns sleep as much and as long as they need to. Between 4 and 12 months, babies move to two naps a day, one in the morning and one in the afternoon, each ranging from 20 minutes to three hours.In their second year, most toddlers go down for one two-hour nap in the middle of the day, and by their third birthdays, some will have given up naps entirely.razelton's view. At this age it's fine to give up naps entirely if your toddler doesn't need or want one. If he does still need a rest during the day, make sure it's not after 3 p.m., as that will break up his activity cycle and cut down on his need for sleep at night.