Homework Help: Minimizing a vector in a triangle

1. Jul 27, 2010

Shaybay92

1. The problem statement, all variables and given/known data

A truck is to be towed using two ropes. If the resultant force is to be 950N, directed along the positive x axis, determine the magnitudes of forces F1 and F2 acting on each rope and the angle at which rope two pulls to ensure that the magnitude of F2 is a minimum. F1 acts at 20 degrees from the x axis.

3. The attempt at a solution

I assumed that to minimize the work required by rope two, it would be -90degrees angle (so it is only required to pull the truck back in line). However, the book says -70degrees?

2. Jul 27, 2010

tiny-tim

Hi Shaybay92!

(have a degree: º )
Sorry, no idea what you mean.

Anyway, just draw a vector triangle …

you know the direction and length of one side, and you know the direction of the second side …

what is the shortest the third side can be?

3. Jul 27, 2010

ghost2

I'm assuming based on the wording that there's a diagram that goes with this? It's kinda hard to solve a geometry problem if there's supposed to be a picture with it.