Ahunter wishes to cross a river that is 1.74 km wide and flows with a speed of 2.68 km/h parallel to its banks. the hunter uses a small powerboat that moves at a maximum speed of 16.9 km/h with respect to the water. what is the minimum time necessary for crossing? answer in units of min.

Minimum time = 6.177 min

Explanation:

We assume a reference system with the positive x-axis (from left to right) and also a positive y-axis (from bottom to top)

According to this system the velocity vector of the river and the hunter are :

The velocity vector of the hunter relative to the ground is the sum of the previously mentioned velocities

This means that,for example,in an hour the hunter moves 16.9 km in the positive x direction and 2.68 km in the negative y direction

We are looking for a displacement of 1.74 km in the x direction ⇒ We will use only the ''i'' component of the velocity

We multiply the time in hours by 60 to obtain the time in minutes

time T = 6.177 min