A boat can travel at 5.0 m/s in still water. It attempts to cross a river 60 m wide with a current of 3.0 m/s downstream. If the boat aims directly across, how long does it take to reach the opposite bank?
Explanation
📌 The boat's velocity perpendicular to the flow is 5.0 m/s (the current does not affect the crossing time). Time = width / perpendicular speed = 60/5.0 = 12 s. Distractor B assumed resultant speed (√(5² + 3²) = 5.83, giving 10.3); C used current speed only; D used sum of speeds.