A boat can travel at relative to still water. It heads directly across a river flowing at . What is its speed relative to the bank?
Answer and explanation
Correct answer: A.
- Step 1: The two velocities are at right angles, so use Pythagoras.
- Step 2: Speed m/s.
Answer
.
Why not the others: : adds the speeds as though they were in the same direction. : subtracts the speeds. : multiplies the speeds.
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