velocity of projection

Using the equation, regarding the projection angle as a small quantity, neglecting the differentiation of the absolute value of the tangential velocity with respect to the time, the P.C. Chou formula was easily obtained.

利用爆轰驱动平板的抛射角方程，在小抛射角条件下，假设切向速度大小随时间的变化率为零，很容易得到周培基（P.C.Chou）公式。

Both of the observed radial velocity and separation being projective values, in order to determine the mass of binary galaxies the average projection factor may be derived by a statistical method.

双重星系或天体系统，用动力学方法测定其质量时，观测到的视向速度和距离间距，都是各自值的投影值，可用统计方法，求出一个关于它们的平均投影因子。