Pythagorean theorem states that the squared value of longest side in an right angle triangle will be equal to the addition of the squared value of two smaller sides. Thus, the resultant speed of the boat is 9.4 m/s.
This is the concept of application of the Pythagorean theorem.
The boat is traveling in the east direction at a speed of 8 m/s but the river has a northward current of 5 m/s. We know than both the directions (East and North) are perpendicular to each other. The bend tending toward east but the river slows down the speed and makes the boat tending toward north-east.
Thus, by applying Pythagorean theorem, the resultant speed can be calculated as:
[tex]\begin{aligned} c^2&=a^2+b^2\\c^2&=8^2+5^2\\c^2&=64+25\\c^2&=89\\c&=\sqrt89 \\c&=9.4\;\rm{ m/s}\end{aligned}[/tex]
Hence, the resultant speed of boat is 9.4 m/s.
To know more about resultant speed, please refer to the link:
https://brainly.com/question/17129763
