A student pulls a rope attached to a box of books and moves the box down the hall. The student pulls with a force of 185 N and an angle of 21.0° above the horizontal. The box has a mass of 45.0 kg and the coefficient of kinetic friction between the box and the floor is 0.27. Find the acceleration of the box.
1.2 m/s2
4.1 m/s2
2.8 m/s2
3.8 m/s2