How Does River Flow Affect a Swimmer's Resultant Velocity?

[dance_sg]

1.A girl can swim 4.5m/s. If she tries to swim across a river flowing at 3.8m/s, what is her resultant velocity?



2. cosine, sine, tangent, v=v_f -v _i



3. would i just subtract 3.8m/s from 4.5m/s in order to find the velocity?

 

[RoyalCat]

Note, she is swimming ACROSS a river, not against the stream.
$$\vec V_{12}= \vec V_1-\vec V_2$$

 

[dance_sg]

So you would add the two numbers rather then subtract them??

 

[dance_sg]

oh oops. i meant to say that i would subtact 4.5 from 3.8 instead and it would be negative?

 

[turin]

vector addition.