## College Physics (4th Edition)

(a) $\mu_k = 0.75$
The correct answer is: (a) $\mu_k = 0.75$ Since the heater moves with a constant velocity, the force of kinetic friction must be equal in magnitude to the applied force of 600 N. $F_N~\mu_k = 600~N$ $(800~N)~\mu_k = 600~N$ $\mu_k = 0.75$