Chapter 6, Problem 69P

A student, crazed by final exams, uses a force $\stackrel{\to }{P}$ of magnitude 80 N and angle θ = 70° to push a 5.0 kg block across the ceiling of his room (Fig. 6-52). If the coefficient of kinetic friction between the block and the ceiling is 0.40, what is the magnitude of the block’s acceleration?

Figure 6-52 Problem 69.