I have a plastic tube 30 Inches in diameter and 10 Inches height, It is completely open on one side of which I insert a plastic plunger 0.5 Inches thick. The other side is closed but has a hole 5 Inches radius. Considering plastic to plastic friction coefficient and also factor in negative pressure. 1. Calculate friction assuming force applied on the plunger is 500lb. 2. Show in calculation the effect of applying a lubricant. 3. What amount of force can efficiently move the plunger up and down? Your assistance is appreciated.