   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.
9 months old: 14 hours a day. The ratio of day to night time sleep moves more towards the night, with around 11.25 hours at night and 2.75 hours in the day. 1 year old: 14 hours per day. As your child moves past the first year towards, they will probably start to lose their morning nap and nap only once a day.While toddlers may need up to 14 hours a day of sleep, they typically get around 2.5 hours in the day and 11.5 at night.3 years old: 12 hours per day. Children at this age typically go to bed between 7pm and 9pm and wake up around 6am or 8am, just as they did when they were younger.here are no hard and fast rules about the exact number of hours of sleep children need at different ages. The NHS offers some broad recommendations developed by the private Millpond Children 's Sleep Clinic: 1-4 weeks old: 15.5-16.5 hours per day. Newborns typically sleep in short periods of two to four hours.