The tertiary then merely responds to the gravitational attraction of the primaries. For example, moons of the planets in our solar system. The tertiary partakes in the rotational motion of the primaries because it is located at one of five Lagrangian points. Linear momentum is conserved. If kinetic energy is conserved, the collision is termed elastic .
Some materials provide values of e which increase or decrease with initial velocity v.
In particle-scattering theory, the impulse approximation corresponds to regarding the time interval as approaching zero, so that F is a delta function. Best illustrated by taking examples.