Question

A boat is sailing at a velocity $3\hat{i}+4\hat{j}$ with respect to ground and water in river is flowing with a velocity $-3\hat{i}-4\hat{j}$. Relative velocity of the boat with respect to water is :-

• A. $8\hat{j}$
• B. $5\sqrt{2}\hat{j}$
• C. $6\hat{i}+8\hat{j}$
• D. $-6\hat{i}-8\hat{j}$

Answer 1

The correct option is C $6\hat{i}+8\hat{j}$

${\overrightarrow{v}}_{bw}={\overrightarrow{v}}_{bg}-{\overrightarrow{v}}_{wg}=(3\hat{i}+4\hat{j})-(-3\hat{j}+4\hat{j})-(-3\hat{i}-4\hat{j})=6\hat{i}+8\hat{j}$