Question Detail
Question
A motorboat heads straight across a river (perpendicular to the bank) at 4 m/s. The river current flows at 3 m/s parallel to the bank. What is the magnitude of the boat's resultant velocity relative to the shore?
Correct Answer
Option B is the correct answer.
Detailed Explanation
The boat's velocity and the river's velocity are perpendicular. The resultant velocity is the vector sum, and its magnitude can be found using the Pythagorean theorem: v = √(v_boat² + v_river²) = √(4² + 3²) = √(16 + 9) = √25 = 5 m/s.
Hint
When two velocity vectors are perpendicular, you can use the Pythagorean theorem to find the magnitude of the resultant vector.