7.5 through 7.8 For the given state of stress, determine (a) the prin- cipal planes, (b) the principal stresses.

Fluid mechanics problem

Control volume concept can be used to obtain forces in both internal and external flow. By drawing a control volume around a region of fluid to expose the stresses acting on the boundaries and applying the conservation of mass and conservation of momentum in integral form, the net forces acting on the fluid and hence the reaction forces acting on the solid boundary can be calculated. The advantages of this approach over differential approach are: (i) It is an easy way to obtain net forces. (ii) It gives a detailed understanding of how these forces are generated. (iii) It is commonly used in engineering practice to obtain reaction forces on pump, turbine, elbow, etc. for the design of anchoring fixtures/foundation. (A) (B) (C) (D) (i) and (ii) (i) and (iii) (ii) and (iii) All of the above

K = 1.4*10-4