1. The problem statement, all variables and given/known data Hello, I was doing a dynamics question, but my answer didn't match the answer key. I want to see if I am wrong, or the book is. The answer in the book is 2100 N. Question: You are helping a friend move, and you need to load a 265 kg box of books. You slide the box up a ramp, which has an incline of 30 degrees, and a coefficient of static friction of 0.45. You apply he force on the box at an angle of 39 degrees with respect to the ramp. Calculate the minimum force needed to slide the box up the ramp. 2. Relevant equations Fnet=ma Fs=(us)(Fn) Fg=Mg 3. The attempt at a solution Fn=(265)(9.8)cos30 =2250 N Fs=us x Fn =0.45 x 2250 =1012.5 <---This is the force needed to be overcome just to move the box Also there is a force of gravity we must overcome Fgx=(265)(9.8)(sin30) =1298.5 This force of gravity in the x coordinate also must be overcome, so Fax must be Fgx + Fs Fax=1012.5 + 1298.5 =2311 N However this is the force that must be applied in the x coordinate, the force is actually being put on the box at an angle of 39 degrees so: Fay/sin 39 = 2311/ sin51 Fay=1871.4 Fa=root (1871.4 ^2 + 2311 ^2) = 2973.7 N So obviously that doesnt match the answer key, can someone please see if my steps are correct, as well as my question understanding, and if so, is the answer key wrong?