Homework Help: STATICS problem: Minimum Resultant Force

Tags:
1. Jan 26, 2016

SnaggleSquatch

Problem Statement: If the resultant force acting on the bracket is required to be a minimum, determine the magnitude of F1 and the resultant force. Set ∅=30 deg.

I have found the components of each force and set them up into a resultant vector, with F1 solved symbolically into its components. I'm not sure how to find the magnitude of F1 so that the resultant is a minimum.

Also, what is the significance of the 'u' axis?

I understand I have to take the derivative of the resultant but I'm not sure how its done. Any help is appreciated, Thanks!

2. Jan 26, 2016

RUber

You should have something that looks like $R=(A+x)\hat x + (B + y)\hat y$ where x and y are the components of F1. Minimize the magnitude of R.
Using the angles, you should be able to write x and y in terms of magnitude times either sine or cosine to get them to one variable.
Then you can use the standard derivative with respect to magnitude variable to find the minimum.