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Inner Tube River Crossing
Activity Information
Learning Goals
- Use vectors to mathematically determine:
- Relative velocity within inner tube-river system
- Launch angle
- Use code to model relative motion
Prior Knowledge Required
- Relative velocity
- Vector addition
- Vector decomposition
- $\sin$ and $\cos$ functions
- $\arctan$ function
Code Manipulation
- Interpret code
- Modify variables within existing code
Activity
Handout
Inner Tube River Crossing
Part 1 It is a hot summer day, and you are meeting your friends for a picnic lunch down by the river. When you get to the river, you discover you are on the wrong side, 20 meters from the picnic site. As an experienced inner tuber, you know that you can paddle your tube at a speed of 2.0 m/s. Additionally, you know the river moves westward at a speed of 1.5 m/s. Your friends have already started the grill and your meal will be ready in 15 seconds.
You have an app that lets you enter your velocity and the velocity of the river to determine your net velocity.
- If you were to get in the river and begin paddling directly across, what velocity (magnitude and direction) do your friends see you moving relative to the shore?