a boat is traveling east across a river that is 112 meters wide at 8 meters per second. if the river has a…

Explanation:

Step1: Identify velocities as vectors

The boat's velocity across the river $v_x = 8$ m/s (east - direction) and the river - current velocity $v_y=5$ m/s (north - direction).

Step2: Use the Pythagorean theorem for vector addition

The resultant velocity $v$ of two perpendicular vectors is given by $v=\sqrt{v_x^{2}+v_y^{2}}$. Substitute $v_x = 8$ m/s and $v_y = 5$ m/s into the formula: $v=\sqrt{8^{2}+5^{2}}=\sqrt{64 + 25}=\sqrt{89}$.

Step3: Calculate the value

$\sqrt{89}\approx9.4$ m/s.

Answer:

B. 9.4 m/s