Question

A boat is moving with velocity $3\hat{i}+4\hat{j}$ with respect to ground. The water in the river is moving with velocity $-3\hat{i}-4\hat{j}$ with respect to ground. The relative velocity of the boat with respect to water is

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

Answer 1

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

Relative velocity of boat w.r.t. water: $v_{bw}=(3\hat{i}+4\hat{j})-(-3\hat{i}-4\hat{j})=6\hat{i}+8\hat{j}$