Bonjour j'ai une question dans la physique moderne, je ne suis pas sure si je l'ai compris d'une facon correcte.
Donnée:
A swimmer capable of swiming at a speed c in still water is swiming in a
stream in which the current is u (which we assume to be less than c). Suppose
the swimmer swims upstream a distance L and then returns downstream to the
starting point. Find the time necessary to make the round trip, and compare it
with the time to swim across the stream a distance L and return.
Méthode:
time=L/(c-u) + L/(c+u)
mais je n'ai pas compris comment "to make the round trip"
Merci d'avance
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