Answer:[tex]v_{b}=\hat{i}+3\hat{j}[/tex]
Explanation:
Given
Width of river [tex]b=200\ m[/tex]
Velocity of boat w.r.t river [tex]v_{br}=3\ m/s \quad [\text{North}][/tex]
Velocity of river [tex]v_r=1\ m/s[/tex]
Now using relative velocity concept
[tex]v_{br}=v_{b}-v_{r}[/tex]
Suppose river is flowing towards east
so [tex]v_{r}=1\hat{i}[/tex]
and [tex]v_{br}=3\hat{j}[/tex]
So
[tex]v_{b}=v_{br}+v_r[/tex]
[tex]v_b=3\hat{j}+\hat{i}[/tex]
[tex]v_{b}=\hat{i}+3\hat{j}[/tex]
So, boat appeared to be moving towards north-east
