Perfectly elastic collisions are those in which no kinetic energy is lost in the collision. Macroscopic collisions are generally inelastic and do not conserve kinetic energy, though of course the total energy is conserved as required by the general principle of conservation of energy.
Ector, Texas. Not to be confused with Ector County, Texas. Ector is a city in Fannin County, Texas, United States. The population was 695 at the 2010 census, up from 600 at the 2000 census.
Shelby County is a county located in the far eastern portion of the U.S. state of Texas. As of the 2010 census, its population was 25,448. Its county seat is Center. The county was created in 1835 as a municipality of Mexico and organized as a county in 1837.