Question

a river is flowing with velocity 2i+3j and boat is moving with 4i+j with respect to the ground. then the relative velocity of boat with respect to the river is

• A. $6i+2j$
• B. $2i-2j$
• C. $i+j$
• D. $4i-3j$

Answer 1

The correct option is B $2i-2j$

Given,

Velocity of boat with respect to the ground,

$v_{BG}=4\hat{i}+\hat{j}$

Velocity of river with respect to the ground,

$v_{RG}=2\hat{i}+3\hat{j}$

The relative velocity of boat with respect to the river is,

$v_{BR}=v_{BG}-v_{RG}$

$v_{BR}=(4\hat{i}+\hat{j})-(2\hat{i}+3\hat{j})$

$v_{BR}=2\hat{i}-2\hat{j}$