An artificial satellite orbiting the earth in very thin atmosphere loses its energy gradually due to dissipation against atmospheric resistance, however small. As it comes closer and closer to earth, its speed ___________

Gravitation topics include: Forces of nature, inertia, restitution coefficient, gravitational and gravity.

The coefficient of restitution (COR) is a unitless quantity that indicates the elasticity of a collision. It is the ratio of the final velocity to the initial velocity between two objects after their collision. The COR is denoted as "e" and its values range between 0 and 1.