Rigid body possible to reconstruct the position of all the other particles, provided that their time-invariant position relative to the three selected particles is known. However, typically a different, mathematically more convenient, but equivalent approach is used. The position of the whole body is represented by: Thus, the position of a rigid body has two components: linear and angular, respectively. The same is true for other kinematic and kinetic quantities describing the motion of a rigid body, such as linear and angular velocity, acceleration, momentum, impulse, and kinetic energy. The linear position can be represented by a vector with its tail at
Lean body mass various technologies such as Dual-energy X-ray absorptiometry (DEXA). Lean body mass Lean body mass (LBM) is a component of body composition, calculated by subtracting body fat weight from total body weight: total body weight is lean plus fat. In equations: The percentage of total body mass that is lean is usually not quoted – it would typically be 60–90%. Instead, the body fat percentage, which is the complement, is computed, and is typically 10–40%. The lean body mass (LBM) has been described as an index superior to total body weight for prescribing proper levels of medications and for assessing metabolic