Hydrostatic Forces on Surfaces topics include: Hydrostatic force on plane area, pressure distribution in liquid, horizantal and inclined plane in liquid, total pressure and vertical plane surface. Hydrostatic forces are the result of a liquid's pressure loading on submerged surfaces. They are always perpendicular to the surface and their magnitude depends on the surface's depth, surface area, and fluid density. The formula for the hydrostatic force on a plane surface is: F = ∫ A P d A F = P c p · A  Where P c p is the pressure at the centroid of the plane surface.  The formula for the... Show more

Hydrostatic Forces on Surfaces topics include: Hydrostatic force on plane area, pressure distribution in liquid, horizantal and inclined plane in liquid, total pressure and vertical plane surface.

Hydrostatic forces are the result of a liquid's pressure loading on submerged surfaces. They are always perpendicular to the surface and their magnitude depends on the surface's depth, surface area, and fluid density.

The formula for the hydrostatic force on a plane surface is: F = ∫ A P d A
F = P c p · A 
Where P c p is the pressure at the centroid of the plane surface. 

The formula for the hydrostatic force on a curved surface is: F = ρgA(h + d) 
Where ρ is fluid density, g is acceleration due to gravity, A is the surface area, h is the depth of the fluid above the centroid of the area, and d is the distance to the centroid. 
Hydrostatic forces differ on horizontal, vertical, or inclined surfaces. They depend on the point's depth from the water's free surface.

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Fluid Mechanics Practice Test: Hydrostatic Forces on Surfaces

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25 Questions

1. What is the variation of total pressure with depth for any submerged surface if we neglect variation in the density?

CurvilinearLinearParabolicLogarithmic

2. What will be the depth (in m) of the centre of pressure for a vertical square lamina submerged in a tank of oil (S=0.8) as shown in the figure?

1.951.651.751.45

3. A square lamina (each side equal to 2m) is submerged vertically in water such that the upper edge of the lamina is at a depth of 0.5 m from the free surface. What will be the depth (in m) of the centre of pressure?

1.521.721.421.32

4. The pressure intensity at the bottom remains same, even if the tank moves with constant horizontal acceleration.

MaybeDon't KnowTrueFalse

5. A rectangular lamina of width b and depth d is submerged vertically in water, such that the
upper edge of the lamina is at a depth h from the free surface. What will be the expression for the depth of the centre of pressure?

\(h + \frac{d}{6} × \frac{3h+2d}{h+2d}\) \(h + \frac{d}{3} × \frac{3h+2d}{2h+d}\) \(h + \frac{d}{3} × \frac{3h+2d}{h+d}\) \(h + \frac{d}{3} × \frac{2h+d}{3h+2d}\)

6. What will be the total pressure (in kN) on a vertical square lamina submerged in a tank of oil (S=0.9) as shown in the figure?

35.326.544.161.7

7. The total pressure or pressure intensity is zero for any point on inclined surface in space.

Don't KnowFalseMaybeTrue

8. A beaker contains water up to a height of h. What will be the location of the centre of pressure?

h⁄3 from the surfaceh⁄6 from the surface2h⁄3 from the surfaceh⁄2 from the surface

9. Which principle is used for calculating the centre of pressure?

Principle of balancing of momentumPrinciple of momentumPrinciple of conservation of energyNone of the mentioned

10. The greatest and the least depth of a circular plate of 4 m diameter from the free surface of water are 3m and 1 m respectively as shown. What will be the total pressure in (kN) on the plate?

246123185308

11. The magnitude of total pressure and centre of pressure is independent on the shape of the submerged plane surface.

TrueFalseDon't KnowMaybe

12. A large tank of height h is filled with a liquid of density ρ. A similar tank is half-filled with this liquid and other-halffilled with another liquid of density 2ρ as shown. What will be the ratio of the instantaneous velocities of discharge through a small opening at the base of the tanks? (assume that the diameter of the opening is negligible compared to the height of the liquid column in either of the tanks)
"

2 : 32 : √3√2 : 3√2 : √3

13. A rectangular plan surface 5 m wide and 7 m deep lies in water in such a way that its plane makes an angle 60⁰ with the free surface of water. Determine the total pressure force when the upper edge is 3 m below the free surface.

311.15 N/cm2622.3 N/cm2None of the mentioned155.5 N/cm2

14. In a vertically submerged plane surface, pressure at evbery point remains same

Don't KnowTrueFalseMaybe

15. A cubic tank is completely filled with water. What will be the ratio of the hydrostatic force exerted on the base and on any one of the vertical sides?

2:13:21:11:2

16. A pipe line which is 6 m in diameter contains a gate valve. The pressure at the centre of the pipe is 25 N/cm2. If the pipe is filled with specific gravity 0.8, find the force exerted by the oil upon the gate.

28.24 MN14.12 MN3.53 MN7.06 MN

17. There will be development of shear stress due to the dynamic motion of tank or container.

FalseTrueMaybeDon't Know

18. Find the total pressure on a circular plate of diameter 3 m immersed in a fluid of specific gravity 0.75 at a depth of 5 m from the surface on a planet having acceleration dueto gravity 7 m/s².

37 N/cm2None of the mentioned18.5 N/cm29.25 N/cm2

19. A rectangular lamina of width b and depth d is submerged vertically in water, such that the upper edge of the lamina is at a depth h from the free surface. What will be the expression for the depth of the centroid (G)?

hh + d / 2h + dh + d ⁄ 2

20. A tank containing water upto a depth of 650 mm is stationary. Find the force exerted by fluid of specific gravity .55 on the side of tank,width of tank is 1.5m

1367.75 N3419.4N6838.8 N1709.9 N

21. A rectangular tank is moving horizontally in the direction of its length with a constant acceleration of 4.5 m/s2.The length, width and depth of tank are 7 m, 3m, 2.5m respectively. If tank is open at the top then calculate the total force due to water acting on higher pressure end of the tank.

1.07 MN2.14 MN4.28 MN4.35 MN

22. If the tank is moving vertically, which of its component is subjected to maximum total pressure?

Lower part of vertical wallsHigher part of vertical wallsNone of the mentionedBase

23. The upper and lower edges of a square lamina of length 4 m are at a depths of 1 m and 3 m respectively in water. What will be the total pressure (in kN) on the lamina?

235.44156.96392.4313.92

24. A cuboidal beaker is half filled with water. By what percent will the hydrostatic force on one of the vertical sides of the beaker increase if it is completely filled?

300200100400

25. Can centre of pressure for a vertical plane submerged surface be ever be above centre of Gravity

It can be above in cases where the surface height is very largeYesNone of the mentionedNo