A sailor wants to travels due east at a velocity of 15km/h with respect to a coordinate system fixed to the ground.

The sailor must contend with the gulf stream, which moves north at 5 km/h. With which veolcity with respect to the water should the sailboat proceed under sail?

to try solve it I set :

V

_{bg}= velocity of boat relative to ground.

V

_{wg}= velocity of water relative to ground.

V

_{bw}= velocity of boat relative to water.

now I wrote: V

_{bg}= V

_{bw}+V

_{wg}but For me it does not fit.

What would fit is :

V

_{bw}= V

_{bg}+V

_{gw}

here

**V**is not defined in the problem!

_{gw}please can someone can help me?

Also, to find the angle θ of the boat, I am confused about what ( and where)put in the equation θ =tan

^{-1}(y/x)

Thank you

brad