   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.
Their growing imaginations can start to interrupt sleep, too. Now more than ever, a simple and consistent bedtime routine is a parent's best bet for getting a sleepy toddler snugly into bed. How Much Sleep Does My Toddler Need? Between the ages of 1 and 2, most kids need about 12-14 hours of sleep a day, including one or two daytime naps. At around 18 months, or sometimes sooner, most toddlers condense their two naps into one afternoon nap. If you find that your toddler fights the morning nap, he or she is probably ready for just an afternoon nap. Where Should My Toddler Sleep? Your 1- to 2-year-old should still sleep in a safe, secure crib. Before a child's first birthday, blankets are not recommended because of the possible risk of sudden infant death (SIDS) syndrome. But at this age, it's OK to put a light blanket in your child's crib.