Question

If the swimmer swim in such a way that his displacement in the direction of river flow is zero then the angle between his velocity with respect to river and direction of river flow is:

• A. ${127}^o$
• B. ${143}^o$
• C. ${37}^o$
• D. ${53}^o$

Answer 1

Answer: (B)

${143}^o$

Given : $V_{SR}=5m/s$ $V_R=4m/s$

For horizontal displacement to be zero, $V_{SR}cos\theta =V_R$

$\therefore$ $5cos\theta =4$ $⟹cos\theta =0.8$ OR $\theta ={37}^o$

$\therefore$ Angle between $V_R$ and $V_{SR}$ $\varphi ={180}^o-{37}^o={143}^o$