PHYSICS · Subjective · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
Two motorboats move north along a straight river. Boat A travels at 4 m/s relative to the water, and Boat B travels at 6 m/s relative to the water. The river current flows north at 2 m/s relative to the ground. Three observers measure the velocity of Boat B:
1. A person on Boat A
2. A person standing on the riverbank
3. A swimmer drifting motionless relative to the water
Rank the magnitude of Boat B’s velocity as measured by observers 1, 2, and 3 from greatest to least.