At the beginning of a new school term, a student moves a box of blocks by attaching a rope to the box and pulling with a force of F= 84.9N at an angle of 65 degrees, as shown in the figure. The acceleration of gravity is 9.8 m/s2. The box of books has a mass of 15 kg and the coefficient of kinetic friction between the bottom of the box and the floor is 0.26. What is the acceleration of the box?