   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.
Q: How many words should my 2-year-old be able to say? A: Around their second birthday, many children begin to acquire words at breakneck speed, a phenomenon experts call the naming explosion. Most 2-year-olds can say about 100 words. By the time your toddler is 2 1/2, she'll probably know close to 300. But not all children follow this pattern, so don't panic if your child isn't talking nonstop by 2 1/2.