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.
The crumple zone is a structural feature mainly used in automobiles and recently incorporated into railcars. Crumple zones are designed to absorb the energy from the impact during a traffic collision by controlled deformation by crumpling. This energy is much greater than is commonly realized. A 2,000 kg car travelling at 60 km/h, before crashing into a thick concrete wall, is subject to the same impact force as a front-down drop from a height of 14.2 m crashing on to a solid concrete surface. I