In the figure, the lever arm, l, is distance r from the hinge to the point at which you exert your force. The torque is the product of the magnitude of the perpendicular force multiplied by the lever arm.
Children normally need a certain number of calories each day (energy allowance) that their bodies use as energy for normal daily activities (walking, breathing, etc.). This ranges for boys from 2000 calories for a 7-10 year old, 2500 calories for an 11-14 year old, and 3000 calories for a 15-18 year old. For girls the ranges are from 2000 calories for a 7-10 year old, to 2200 calories for an 11-18 year old. These are only estimates and some children need more (fast metabolism) or less (slow metabolism) of an energy allowance for daily activities.
While many 2-year-olds generally require about 1,000 calories per day, 3-year-old girls need about 1,000 to 1,400 calories and 3-year-old boys often require 1,200 to 1,400 calories daily to grow at a healthy pace, according to the Dietary Guidelines for Americans 2010.our childâs individualized calorie needs are based on age, gender and activity level. Ask your pediatrician to track your child's growth to make sure heâs growing at an appropriate pace compared to other children the same age.