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.
Girls aged 11 to 13 need 1,800 to 2,200 calories per day while those between the ages of 14 and 18 need 1,800 to 2,400 calories per day, according to the Academy of Nutrition and Dietetics.One of the main factors affecting the calorie needs of teenagers is activity level.Teenagers who are sedentary need to consume fewer calories than those who are more active. Very active teenage boys who play sports like football, soccer or basketball may need up to 3,500 calories per day.alorie Ranges. Boys between the ages of 11 and 13 need 1,800 to 2,600 calories per day while boys ages 14 to 18 need between 2,200 to 3,200 calories per day.