Center of mass reference point R are and If R is chosen as the center of mass these equations simplify to where "m" is the total mass of all the particles, p is the linear momentum, and L is the angular momentum The Law of Conservation of Momentum predicts that for any system not subjected to external forces the momentum of the system will remain constant, which means the center of mass will move with constant velocity. This applies for all systems with classical internal forces, including magnetic fields, electric fields, chemical reactions, and so on. More formally, this is true for any
Body mass index Body mass index The body mass index (BMI) or Quetelet index is a value derived from the mass (weight) and height of an individual. The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/m, resulting from mass in kilograms and height in metres. The BMI may also be determined using a table or chart which displays BMI as a function of mass and height using contour lines or colours for different BMI categories, and which may use other units of measurement (converted to metric units for