>>11089064firstly, kek nice work getting it rotated. secondly, your work is, if im honest, subpar at best, literal garbage at worst. your notation is just fucking terrible and your "logic" does not follow when you simply begin your first line by giving the sum of F (what is F???- state your assumptions and treatments, e.g, you can first say you are "treating the mass+string+mass as our system and thus sum(F)= blah blah where F is the external force on our system")
Also, where did you get u_ks (wtf is ks?)? and if, as the question seems, it asks for the acceleration, is your first line F_f=u*m*g*costheta really true? (hint: no, its an inequality which surely wont be equal for all times when the system is moving). Youre on a great start but I recommend you get a good grasp on notation and what you treat as a system. I didnt learn from a book early on but feynman's lectures are really good and also Taylor if youre up for it (its a verbose treatment so you might be able to do it without much knowledge beyond the appendix). Check the wiki for highschool books if not.
