Sidhu uses a 4.67 m long rope to pull Aarna (m = 59.9 kg) horizontally across the floor with a coefficient of kinetic friction of _k = 0.200 at a constant speed of 3.11 m/s. Aarna signals to Sidhu to stop by "plucking" the rope, sending a wave pulse forward along the rope. The pulse reaches Sidhu 418.0 ms later. What is the mass of the rope?