1. Fluid Mechanics: Mahalingam1 Lecture #7 Recap lecture #6 - Developed equation to describe pressure in the atmosphere Focus of today’s lecture - Verify problem solution you were expected to compete from last lecture - Examine hydrostatic forces on planar submerged surfaces with the goal of finding magnitude and line of action of net hydrostatic force z y x - Applied hydrostatics principles to problems Problem Set # 2, due on Friday, September 10th: 2.10, 2.20, 2.24, 2.28, 2.36

2. Fluid Mechanics: Mahalingam2 Lecture #7 - continued => To Express P c in terms of mm’s of Hg Substitute numerical values D E F G B A C l1l1 l2l2 l3l3 Water

3. Fluid Mechanics: Mahalingam3 Lecture #7 - continued Read section 2.5, MYO, 3rd edition on absolute/gage pressure/textbook convention, concept of pressure head on page 46 Manometry - Demo Assumptions: Static fluid, gravity is the only body force, z axis vertical h1h1 h2h2 A B Read 2.6.3 and 2.7, MYO, 3rd edition for other pressure measuring devices

4. Fluid Mechanics: Mahalingam4 Lecture #7 - continued Hydrostatic forces on submerged surfaces - Begin by considering forces on planar surfaces - Basic ideas are the same when considering curved surfaces Planar surface analysis Goal To find magnitude of force on a planar surface submerged in a fluid To find location of net force or Center of Pressure

5. Fluid Mechanics: Mahalingam5 y z h dy y dF Lecture #7 - continued  Here y c is the y-coordinate of centroid of area ycyc hchc yRyR F x y x dA

6. Fluid Mechanics: Mahalingam6 Lecture #7 - continued Introduce Module 2 briefly (Surface tension module) at the end of lecture At the beginning of lecture, point to website for course http://stripe.colorado.edu/~mcen3021