Answer:
v= 4.9 m/s in east direction ( or v=4.9 m/s * i )
Explanation:
Since the passenger moves along the train ( in the north direction relative to the train) then if the train is traveling east relative to the ground , the passenger will also travel to the east relative to the ground .
Then the magnitude of the velocity will be
v= 1.40 m/S + 3.5 m/s = 4.9 m/s
v= 4.9 m/s
and the direction will be east ( if the x axis represents east direction and y-axis the north direction , then the velocity vector will be v=4.9 m/s * i )