5. Example 2.7
Find the magnitude of the resultant force on this vertical wall of a tank which has oil, of relative density 0.8, floating on water as shown

6. Draw the pressure diagram as shown to the right.
Solution
Draw the pressure diagram as shown to the right.
The resultant force (per unit length) is simply the area of the pressure diagram.
It is convenient to split the area into three, and sum the answers.
F1 = A1 = (0.8 x 103) x 9.81 x 0.8 x 0.8x0.5 =
F2 = A2 = (0.8 x 103) x 9.81 x 0.8 x 1.2 =
F3 = A3 = (103) x 9.81 x 1.2 x 1.2 x 0.5 =
R = F1 + F2 + F3 = N/m
R acts horizontally through the centroid of the pressure diagram.

13. Example 2.8
Find the magnitude and direction of the resultant force (in N not N/m) of water on a quadrant gate as shown below

14. At an angle Horizontal force, RH = Force on projection of curved
surface on to a vertical plane
= 0.5 x rgh2 x width
= 0.5 x 1000 x 9.81 x 12 x 3
= N
Vertical force, RV = weight of fluid above surface
= rg x Area covered
= 1000 x 9.81 x(pr2/4) x 3
= N
Resultant force
At an angle

15. Example 2.8

16. Solution

17. Last Semester First Exam

18. Fluid dynamics and its applications

23. Streamline & Pathline