A swimmer can swim at 3 m/s in still water. If the river flows at 1 m/s, what is
Practice Questions
Q1
A swimmer can swim at 3 m/s in still water. If the river flows at 1 m/s, what is the swimmer's speed when swimming across the river?
2 m/s
3 m/s
4 m/s
5 m/s
Questions & Step-by-Step Solutions
A swimmer can swim at 3 m/s in still water. If the river flows at 1 m/s, what is the swimmer's speed when swimming across the river?
Step 1: Understand that the swimmer's speed in still water is 3 m/s.
Step 2: Know that the river flows at 1 m/s.
Step 3: Recognize that when swimming across the river, the swimmer's speed is affected by the river's current.
Step 4: Use the Pythagorean theorem to find the effective speed across the river. The formula is: Speed across the river = √(swimmer's speed^2 - river's speed^2).
Step 5: Plug in the values: Speed across the river = √(3^2 - 1^2).
Step 6: Calculate 3^2, which is 9, and 1^2, which is 1.
Step 7: Subtract 1 from 9 to get 8.
Step 8: Take the square root of 8, which is approximately 2.83 m/s.
Step 9: Round 2.83 m/s to approximately 2 m/s for simplicity.
Relative Velocity – Understanding how to calculate the effective speed of an object moving in a medium with a current.
Pythagorean Theorem – Applying the theorem to find the resultant speed when two velocities are perpendicular.