An object sits at the edge of a table top with a mass of 180 kg. It is connected by a magical physics thread to a mass of 250 kg via a pulley which is hanging in the air below the edge of the table top. There is an unknown amount of friction between the 180 kg mass and the table. The entire thing is accelerating at 2 m/s/s towards the edge of the table (250 kg mass is moving down).
What is the force of friction?
What is the coefficient of friction?