1. The problem statement, all variables and given/known data A boy and a girl both swim at 3.0m/s. They jump into a river 1.0km wide, with a current of 2.0m/s[E]. a.) The girl swims so that she ends up directly across from her starting point. What is her velocity relative to the ground? 2. Relevant equations Note: V = velocity with arrow above it. Vgw = 3.0m/s (Girl relative to water) Vwg = 2.0m/s[E] (water relative to ground) Vgg = ? [?] (Girl relative to ground) Vgw + Vwg = V[gg] 3. The attempt at a solution I believe I've set it up correctly, although I don't see how to solve it. I know you have to the Pythagorean theorem so it's Vgg2 + 22 = 32. Which turns out to be Vgg + 4 = 9, subtract 4 on each side. Vgg = √5. So Vgg = 2.2m/s. But when looking at this equation: Vgw + Vwg = V[gg], the inner 2 w's must match, then the outer 2 letters must match, so the equation is right. But as you can see in my picture at the bottom half of the page, I get a velocity of -2.2m/s. Which doesn't exist but you can't just get rid of the negative sign, can you? How does it just go away like that? Or did I do something wrong?