A constant velocity means the acceleration is zero.
We all think that sleep has a uniform state of being. This is a wrong connotation but instead, the truth is sleep is composed of several different stages. This can be differentiated from one another by the patterns of brain wave activity that occur during each stage. In the 1st stage of the non-rapid eye movement or NREM, this is when the transitional phase occurs between wakefulness and sleep. This is the period when we drift off to sleep. The heartbeat as well as the respiration rates in the body slow down during this period. Furthermore, in stage 1 there is marked decrease in both overall muscle tension and core body temperature. Stage 1 wave activity s directly associated with the alpha and theta waves. It isa said that it is really easy to wake a person who is still at stage 1 and are not even convinced that he or she has been asleep during this stage.
