The coefficient of kinetic friction between a couch and the floor is 0.81. if the couch has a mass of 71 kg and you push it with a force of 650 n, what is the net force on the couch as it slides? a: 696 n b: 86 n c: 46 n d: 331 n

Place me with this question is my last question

Diego is trying to lift a piano to the second floor of his house. diego uses a pulley system and gives a big lift to the piano.the piano moves upward, then stops, and then it starts to fall to the ground. which list best describes the forces on the piano in the proper order? positive force → balanced force → negative force negative force → balanced force → positive force positive force → unbalanced force → negative force negative force → unbalanced force → positive force

·sound · parallel · mechanical · not a vacuum · needs a medium · compressions and rarefaction what type of wave is being described? a) compaction b) electromagnetic c) longitudinal d) transverse