(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two twins set out to row separately across a swiftly moving river. They have identical canoes, and can row at the same speed in still water. Twin A aims straight across the river but, due to the current, is carried downstream before reaching the opposite bank. Twin B aims her canoe upstream at an angle of 56.0 degrees relative to the riverbank, so as to arrive on the opposite side at a point that is directly across from her starting point.

Calculate the ratio of the time it takes twin A to cross the river to the time it takes twin B to cross.

Determine the direction of twin A's motion, expressed as an angle relative to the downstream direction.

2. Relevant equations

3. The attempt at a solution

In order to find a ratio of time, I set up update of position formulas.

Twin A:

[tex]\Delta[/tex]X=V_{avg}*t

In the case of the x direction I'll call the initial velocity V which should equal Twin B's initial velocity

[tex]\Delta[/tex]X=V*t

time for twin A:

t=[tex]\Delta[/tex]X/V

Twin B:

[tex]\Delta[/tex]X=Vcos34*t

t=[tex]\Delta[/tex]X/Vcos34

Ratio of A/B for t is cos34, I got this part right.

I don't know how to go about the second part. The drag of the water represents a Force vector, and Twin A start off with a velocity vector in the x direction.

What I do know:

Initial y position=0

Initial y velocity=0

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# Homework Help: Vector Problem of two twins

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