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.
Graph comparing stressâstrain curves for brittle and ductile materials. A material is brittle if, when subjected to stress, it breaks without significant plastic deformation. Brittle materials absorb relatively little energy prior to fracture, even those of high strength. Breaking is often accompanied by a snapping sound. Brittle materials include most ceramics and glasses (which do not deform plastically) and some polymers, such as PMMA and polystyrene.