1. The problem statement, all variables and given/known data A horizontal bar is used to support a 75-kg object between two walls. The equal forces F exerted by the bar against the walls can be varied by adjusting the length of the bar. Only friction between the ends of the bar and the walls supports the system. The coefficient of static friction between bar and walls is 0.41. Find the minimum value of the forces F for the system to remain at rest. 2. Relevant equations ? 3. The attempt at a solution I do not have an idea as to where I should start. Thank you.