摘要
运用J=r_c×mv_c+J′公式计算刚体相对瞬心的动量矩等于把质量集中在(以瞬心和质心的联线为直径的)圆周上的任一点相对瞬心的动量矩和刚体相对于圆上这点的动量矩之和.
We can calculate the rigid body's moment of momentum relative to the instantaneous centre by using the formula ' J = rc × mvc + J''. The moment of momentum equals the sum of point'moment of momentum reeative to the instantaneous centre plus the rigid body's moment of momentum relative to this point at the circumference. This point where the mass is concentrated is at the circumference (using the line linking the instantaneous centre with the mass centre as the diametre of the aircle)
