A boat is moving 24.4m/s, 35 degrees North of East against the 10m/s water current that flows towards south. What would be the speed of the boat as it crosses the river
If we let +x be eastward, we have
<19.98,13.99> or, approximately
<20,14>
Add that to <0,-10>
and the resultant velocity is
<20,4>
The (eastward) speed with which the boat is crossing the river is 20m/s.
Not sure whether I interpreted your language correctly, as it is somewhat ambiguous. If I got it wrong, fix the numbers and follow the steps.