   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.
In order to get to an eat-play-sleep routine AND have feedings every 3-4 hours, depending on age, your baby needs to be napping in fairly long intervals (1-2 hours each time or so).his means that your baby wakes up, you feed him, your baby plays, then goes to sleep and repeat this all day long. The book outlines how long between feedings at various ages and indicates your baby should sleep through the night from an early age (around 8 to 12 weeks, for the most part).