Friction: a) comes from microscopic bumps that act as obstructions to the object's motion. b) is the name given to the force acting between surfaces sliding past one another. c) acts in a direction that opposes the motion of an object. d) none of the above e) a, b and c

Aproduction line at v. j. sugumaran's machine shop has three stations. the first station can process a unit in 7 minutes. the second station has two identical machines, each of which can process a unit in 16 minutes (each unit only needs to be processed on one of the two machines). the third station can process a unit in 10 minutes. ▼ is the bottleneck station, with a bottleneck time of nothing minutes per unit (enter your response as a whole number).