In order for energy to be conserved, the final totalkineticenergy must be greater than the initial by this amount.
要符合能量守恒原理，末总动能必须比初动能大这么多。
2
Many of these appear to be fairly uniform, so by the virial theorem the totalkineticenergy should be half the total gravitational binding energy of the galaxies.
多数这些好象是很统一，因此靠维里法则总动能应该是星系总引力聚合能的一半。
3
The totalkineticenergy of a Body or system is equal to the sum of the kinetic energies resulting from each type of motion. The kinetic energy of an object depends on its mass and velocity.