# Introductory Vector Equation Illustrated by a Moving River - Picture Included

1. Oct 11, 2009

### to819

Introductory Vector Equation Illustrated by a Moving River -- Picture Included

1. The problem statement, all variables and given/known data
A swimmer wants to cross a river, from point A to point B, as shown in the figure. The distance (from A to C) is 100 , the distance (from C to B) is 75 , and the speed of the current in the river is 5 . Suppose that the swimmer's velocity relative to the water makes an angle of with the line from A to C, as indicated in the figure.

To swim directly from A to B, what speed , relative to the water, should the swimmer have?

2. Relevant equations

A to B2=1002+752

A to B= 125 meters

That's about all I really know how to do. For some reason I can't think of a way to go about solving this problem. Any ideas?

Last edited: Oct 11, 2009
2. Oct 11, 2009

### ideasrule

Re: Introductory Vector Equation Illustrated by a Moving River -- Picture Included

What's the question?

3. Oct 11, 2009

### to819

Re: Introductory Vector Equation Illustrated by a Moving River -- Picture Included

That's embarrassing, can't believe I left that out. The question is now included.

4. Oct 11, 2009

### to819

Re: Introductory Vector Equation Illustrated by a Moving River -- Picture Included

Hmm, I've looked through all the related threads, however, in all instances the problem is similar a solution is available but documentation showing how the solution is reached is unavailable. I'm much more interested in the necessary steps to solve this problem than the actual solution.