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.
Most of these calories should come from nutritious foods rather than snack foods and fast food so their growing bodies are fueled healthfully. 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.ost of these calories should come from nutritious foods rather than snack foods and fast food so their growing bodies are fueled healthfully. 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.