Concept explainers
A thin
FIGURE P2-77
(a)
The location where the oil velocity is zero.
Answer to Problem 77P
The location where the oil velocity is zero is
Explanation of Solution
Given information:
The cross section of the plate is
The following figure gives the velocity profile of the plate:
Figure-(1)
Write the expression for the viscous force.
Here, the viscous force is
Write the expression for the thickness of the oil film.
Calculation:
Substitute
Substitute
Conclusion:
The location where the oil velocity is zero is
(b)
The force required to maintain the motion.
Answer to Problem 77P
The force required to maintain the motion is
Explanation of Solution
Write the expression for the viscous force.
Here, the viscous force is
Write the expression for the total applied force.
Here, the total force is
Calculation:
Substitute
Substitute
Conclusion:
The force required to maintain the motion is
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