A lecturer, when explaining stress management to an audience, raised aglass of water and asked,"how heavy is this glass of water?" Answers called out ranged from 20g to 500g.The lecturer replied,"The absolute weight doesn't matter. It depends on how long you try to hold it.If I hold it for a minute, that's not a problem.If I hold it for an hour, I'll have an ache in my right arm.If I hold it for
