Answer:
the speed of the boat is 21.22ft/min
Step-by-step explanation:
Hello!
To solve this exercise follow the steps below.
1. Draw the complete scheme of the problem (see attached image).
2. As you can see in the image, our goal is to determine the horizontal component of the velocity (Vx) that corresponds to that of the boat, for this the first thing we do is find the alpha angle using the height and the hypotenuse of the triangle.

3. Finally we find the horizontal velocity component using the cosine function

the speed of the boat is 21.22ft/min