Question

Joana Marie is a swimmer. She swims directly across a river flowing at 4 m/s with a velocity of 2 m/s. What will be the actual velocity of Joana Marie relative to the river? Determine its angle.

Answer 1

Solution.

$v_r=4 m/s;$

$v_s =2 m/s;$

$v=\sqrt{v_r^2+v_s^2};$

$v=\sqrt{4^2+2^2}=4.47 m/s;$

$tan\theta=\dfrac{v_s}{v_r};$

$tan\theta=\dfrac{2}{4}=0.5;$ $\theta=27^o;$

Answer: $v=4.47 m/s; \theta=27^o.$