Performing the Chemical Test by Reagent Strip The urine must be collected using appropriate technique and be tested within one hour ofcollection. If tests cannot be performed within this time, the specimen may be refrigerated for upto 8 hours.
Elastic and Inelastic Collisions. A perfectly elastic collision is defined as one in which there is no loss of kinetic energy in the collision. An inelastic collision is one in which part of the kinetic energy is changed to some other form of energy in the collision. Any macroscopic collision between objects will convert some of the kinetic energy into internal energy and other forms of energy, so no large scale impacts are perfectly elastic.
That's closer to the mark. But still, this apparatus is a special case: collisions between identical spherical, nearly perfectly elastic, balls of equal mass, size and composition. Those special conditions are responsible for the intriguing and special behavior we observe.