1. The problem statement, all variables and given/known data You drag a trunk of mass m across a level floor using a massless rope that makes an angle with the horizontal (figure below). Given a kinetic-friction coefficient (mu). Find the minimum force needed to move the trunk with constant speed. 2. Relevant equations F=ma Fk=µk(Fn) 3. The attempt at a solution What's really getting me is that the site says the answer doesn't depend on theta. I found the normal force being Fn=mg-FsinΘ the total friction force being µk(mg-FsinΘ) For the force equation, F=ma F=0 FcosΘ=µk(mg-FsinΘ) Solving for F, I came up with: F= (-µkmg)/(µksinΘ-cosΘ) Again, says no theta in the answer though. Any pointers?