Answer:
[tex]\overrightarrow{V_{S,G}}=2\widehat{i}-4\widehat{j} mi/h[/tex]
Step-by-step explanation:
velocity of river with respect to ground = 4 mi/h south
[tex]\overrightarrow{V_{R,G}}=4(\widehat{-j})[/tex]
Velocity of swimmer with respect to river = 2 mi/h east
[tex]\overrightarrow{V_{S,R}}=2(\widehat{i})[/tex]
According to the formula of relative velocity
[tex]\overrightarrow{V_{S,R}}=\overrightarrow{V_{S,G}}-\overrightarrow{V_{R,G}}[/tex]
[tex]2\widehat{i}=\overrightarrow{V_{S,G}}+4\widehat{j}[/tex]
Where, V(S,G) be the velocity of swimmer with respect to ground, it is true velocity of swimmer. Â
[tex]\overrightarrow{V_{S,G}}=2\widehat{i}-4\widehat{j} mi/h[/tex]