   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.
Third Month Baby Milestones: Sleep. Your 3-month-oldâs nervous system is maturing, and his stomach can accommodate more milk or formula. Those changes should allow your baby to sleep for a stretch of six or seven hours at a time, which translates into a good night's sleep for you. If your baby does wake up in the middle of the night, wait about 30 seconds before heading into the nursery.