In the rain, does a person get less wet walking or running? To answer this question, some theoretical models have been published over a period of almost 30 years and, according to them, the faster the person moves, the less wet he or she becomes during a certain fixed path in the particular case of a uniform vertical rain. In all these works, however, it is implied that each raindrop that strikes the person is completely absorbed. In this paper, we consider for the first time the fact that each raindrop that strikes the person might not be completely absorbed, and show that still keeping other simplifications, even a relatively simple hypothesis about the absorbed fraction of each raindrop makes the question of walking or running in the rain a nontrivial problem.
modelling; optimizing; mass absorption; rain
