in an anniversary celebration of Marilyn bell's 1954 feat - she was the first person to swim across lake Ontario - a swimmer set out from the shores...

in an anniversary celebration of Marilyn bell's 1954 feat - she was the first person to swim across lake Ontario - a swimmer set out from the shores of New york and maintained a velocity of 4 m/s [N]. as the swimmer approached the Ontario shore, she encountered a cross current of 2 m/s [E 25 S]. calculate her velocity with respect to the crowd observing from the beach (with respect to the ground)