Suppose that an initially empty stack performs (in some order) 18 push operations, 8 peek operations, and 12 pop operations. 3 of the peek operations and 5 of the pop operations return null, indicating that the stack is currently empty. After all of these operations, how many items are in the stack?

Afull journal bearing has a journal diameter of 27 mm, with a unilateral tolerance of -0.028 mm. the bushing bore has a diameter of 27.028 mm and a unilateral tolerance of 0.04 mm. the l/d ratio is 0.5. the load is 1.3 kn and the journal runs at 1200 rev/min. if the average viscosity is 50 mpa-s, find the minimum film thickness, the power loss, and the side flow for the minimum clearance assembly.