# What is Hydrostatic force: Definition and 63 Discussions

Fluid statics or hydrostatics is the branch of fluid mechanics that studies "fluids at hydrostatic equilibrium and the pressure in a fluid or exerted by a fluid on an immersed body".It encompasses the study of the conditions under which fluids are at rest in stable equilibrium as opposed to fluid dynamics, the study of fluids in motion. Hydrostatics is a subcategory of fluid statics, which is the study of all fluids, both compressible or incompressible, at rest.
Hydrostatics is fundamental to hydraulics, the engineering of equipment for storing, transporting and using fluids. It is also relevant to geophysics and astrophysics (for example, in understanding plate tectonics and the anomalies of the Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields.
Hydrostatics offers physical explanations for many phenomena of everyday life, such as why atmospheric pressure changes with altitude, why wood and oil float on water, and why the surface of still water is always level.

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1. ### Resultant force and centre of pressure in a tank

Figure: a) CASE A ##\rightarrow p_a=101300\, \textrm{Pa}## $$F_{\textrm{res}}?,\,\, y_c-y_{cg}=y_{cp}$$ We find ##h_{cg}\rightarrow h_{cg}=3+h## $$h=0,75\cdot \sin (30)=0,375\, \textrm{m}\rightarrow h_{cg}=3,375\, \textrm{m}$$ $$p_{cG}=\rho_{H2O}gh_{cg}=33108,75\, \textrm{Pa}$$ We calculate...

3. ### Finding the magnitude of the hydrostatic force per unit of circumference

Hello all I am trying to find the hydrostatic force of a cylindrical tank of water. I was hoping someone could help point me in the right direction. I have a cylindrical water tank. The dimensions are as follows:- I need to find the magnitude of the hydro static force per unit of...
4. ### Hydrostatics Pressure - Finding thrust and resultants

Homework Statement I'm getting stuck with this one and in need of some direction! Obviously I'm not looking for a direct solution, but maybe a outline of what I should be doing? (I'll attach an image in a few minutes) <Image here incoming!> Known data: d2 = d1 / 2 F = thrust force (N) Pa = ρ...
5. ### What's the difference between hydrostatic force and bouyancy?

Homework Statement Homework EquationsThe Attempt at a Solution
6. ### Hydrostatic force on identical containers filled with equal volumes of water

In the sketch are 2 identical containers filled with equal volumes of water. Which has a greater absolute vertical force only on the conical wall and by what relative amount? Not a classroom or homework problem.
7. ### Determine Force on 6ft Door Due to Water & Air Pressure

Homework Statement Determine the total force and its direction (left or right) due to water and air pressure in the surface shown in Fig. P3.62 (lb f). The door is hinged at the top and is 6 feet wide. See attached image.Homework Equations Fp (force of pressure) = specific weight of fluid *...
8. B

### Hydrualic pressure moving plug in pipe

Homework Statement A plug with a given mass is placed in the end of a horizontal pipe to hold water at a given pressure behind it. Is there any way to calculate how far this plug would move in the x-axis if it suddenly lost it's grip against the pipe wall, and it was situated a given height...
9. ### Forces due to atmospheric pressure won't cancel in an open tank

Homework Statement [/B] I am trying to understand why books always point as a fact that hydrostatic force on the bottom of a open liquid filled tank doesn't depend on the force due atmospheric pressure because they these forces cancels each other. Homework Equations [/B] P=[P][/o]+ρgh F=P*A...
10. ### Determining hydrostatic force on a sphere

Homework Statement A solid sphere with radius ##R## is submerged on water at a depth ##h_1##. Water's specific weight is ##\gamma##. Determine both horizontal and vertical forces exerted by the water on the surface of the sphere, in terms of ##R## and ##\gamma##. Homework Equations My lecturer...
11. ### I Question about Hydrostatic Force?

Hello! I am currently in Calculus 2 and we are dealing with hydrostatic force. I get the integration that happens but I always seem to have trouble with solving the word problems. With this problem, I realize that I use integrate by making an infinite number of rectangles on the 2 triangles. I...
12. ### How Do You Calculate Width in Hydrostatic Force Problems with Varying Depths?

Hello! I am currently in Calculus 2 and we are dealing with hydrostatic force. I get the integration that happens but I always seem to have trouble with solving the word problems. With this problem, I realize that I use integrate by making an infinite number of rectangles on the 2 triangles. I...
13. ### Hydrostatic force on the bottom of a container

Is the force from a liquid against the horizontal bottom of a container a function of depth and cross sectional area at the bottom only, i.e., computed by the formula Force=unit weight of water x depth x cross sectional area? If so the force could be greater than the weight of water and that...
14. ### Basics of hydrostatic force on a plane surface

1. Introduction Pressure of a fluid exerts thrust on each part of a surface with which the fluid made contact. Each forces distributed over the area have a resultant magnitude and direction that is very crucial. For a horizontal surface, the pressure does not vary over the plane. Thus, the...
15. ### Therefore, a = 3 and b = 5.Hydrostatic Force Homework: Find a & b

Homework Statement An object made entirely from one material has a volume of 30m3. It floats in a liquid of density of 3g/cm3 with only half its mass below the liquid's surface. The object is then placed in another liquid of same volume but with a density of 1g/cm3 If the final upthrust that...
16. ### Calculating Hydrostatic Force on a Trapezoidal Shape

It is posted here http://math.stackexchange.com/questions/1290380/how-to-integrate-hydrostatic-force-on-a-two-dimensional-shape and I would really appreciate some insight on this question. I sliced the sections horizontally and could not get the answer.. thank you!
17. ### MHB Help with hydrostatic force questions

Here are the questions... A rectangular swimming pool is 4 feet deep, 75 feet long, and 25 feet wide. It is completely filled with water. a. What is the hydrostatic force on the bottom of the pool? b. What is the hydrostatic force on the shorter wall of the pool? c. What is the hydrostatic...
18. ### Fluid statics- pressure intensity and hydrostatic force

Homework Statement a concrete dam, 20m in height, has a vertical upstream face. if the water level is coincident with the top of the dame, calculate and plot the pressure intensity at 4m intervals over a vertical and thus determine the total hydrostatic force acting per unit width. Show that...
19. ### Finding the total hydrostatic force that can be withstood

Homework Statement [/B] We are given a cubic tank, with a parabolic object y = x^2 (one end is -1, 1 and the other is 1, 1 --> it only goes up to 1). The total pressure it can withstand is 160 lbs. Also, the fluid density is 50 lbs. Find: a) Total pressure if water is 2-feet deep. b) Max...
20. ### Finding the Ratio of Dimensions for Equal Hydrostatic Force on a Vertical Plate

1. A vertical plate consists of rectangular and semicircular portion and has dimensions as shown. It is submerged in a liquid such that the upper edge coincides with the free surface of the liquid. What is the ratio of L/R such that force on the rectangular portion is the same as that on the...
21. ### Hydrostatic force on submerged rectangle

Homework Statement (Referring to attached diagram) Find the hydrostatic force F2 on the rectangular part and the point of action of this force on rectangular area. The triangular part is submerged in oil of specific gravity 0.8, while the rectangular part is submerged in water. The whole...
22. ### Calculating hydrostatic force & locating centre of pressure

Homework Statement A circular viewing window of diameter D = 0.4m is placed in the Holding tank. The top of the window is H = 1.2m below the water surface. Find the hydrostatic force acting on the window and locate the corresponding centre of pressure (CP). There is a diagram attached to the...
23. ### How to Find Hydrostatic Force on a Submerged Plate?

Even problem in textbook.Homework Statement "Set up the integral to find the hydrostatic force on the face of the aquarium water tank, whose cross sectional area can be described by, y = e^-x^2 on 0.5≤x≤4.5 meters, resting at the bottom of the water 4 meters deep. Assume the bound y=0". The...
24. ### Hydrostatic force and pressure

Homework Statement The question asks to find the pressure force on the gate A-) centered on a tanker under 3m of water sector and on the cover plate is manufactured to calculate the net hydrostatic force. B-) Determine the location of the center of pressure. (With seal liquid...
25. ### Solve Hydrostatic Force w/ Triangle Plate - Math Homework

Homework Statement A triangular plate with height 6 ft and a base of 8 ft is submerged vertically in water so that the top is 3 ft below the surface. Express the hydrostatic force against one side of the plate as an integral and evaluate it. (Recall that the weight density of water is 62.5...
26. ### Vertical hydrostatic force acting upwards on a curved surface?

Homework Statement I am only confused about F_y. The Attempt at a Solution I don't understand why in the equation F_y = ρghcA, the hc is 5m. Why do they take the centroid distance to be the very bottom?
27. ### Hydrostatic force incline plane

I understand all the concepts, the only thing I don't know is were does Yc=hc/sin 60 comes from. Im kind of visual, if you could upload how you do it, it would help
28. ### Hydrostatic Force in swimming pool

A swimming pool is 20 ft wide and 40 ft long and its bottom is an inclined plane, the shallow end having a depth of 3 ft and the deep end, 9 ft. If the pool is full of water, estimate the force on one of the sides. They mean one of the trapezoidal sides, not the rectangular ones. Anyway, I've...
29. ### Moment of the Hydrostatic Force on a body

This problem is for a Fluid Dynamics course, but it is mostly math and thus I figured it should be posted here. If it should be moved elsewhere, please let me know and I will do so! Homework Statement We saw in class the hydrostatic force acting on a body at rest in an incompressible...
30. ### Hydrostatic force on a plane surface

Homework Statement im required to find the width of the strip of integration across the triangular lamina w(s) and then integrate to find the area I am given w(s) = x_right(s) - x_left(s) between 0<s<λh and λh<s<h Homework Equations The Attempt at a Solution i have...
31. ### Hydrostatic force on a plane surface

i have this example of a hydrostatic force on a plane surface. what i don't understand is how the width of the integral strip is derived it says w(s)=b(s-s1)/L i don't understand how this comes about? would be really greatful if anyone could direct me i can't find anything on...
32. ### What Is the Hydrostatic Force on One End of a Tank Filled with Gasoline?

1. Homework Statement A large tank is designed with ends in the shape of the region between the curves y =(1/2)x^2 and y = 12, measured in feet. Find the hydrostatic force on one end of the tank if it is filled to a depth of 8 ft with gasoline. (Assume the gasoline's density is 42.0 lb/ft^3)...
33. ### How Do You Calculate Hydrostatic Force and Moments in Curved Apparatus?

Using the picture added Q4, work out the hydrostatic force applied to AB when the water level is at 9cm and 12.8cm. 50g of weight was added to balance the setup. And 260g and 460g were used respectively. width of container was 75mm Also need the moments Heres what I've done F...
34. ### Hydrostatic Force on a Plane Surface

Homework Statement I am confused with the derivation of Hydrostatic force on a plane surface. What is confusing me is, how can the integral of the differential force get the resultant force for the entire area of the surface? The differential force is as follows: dF = ρgh dA and the...
35. ### Hydrostatic Force on a Plate: Solving with Reimann Sums and Integrals

Homework Statement Find the hydrostatic force against one side of the plate by Reimann sum. Then express the force as an integral and evaluate it.Homework Equations F=pg*Ad pg do not need to be solved. they can be left like that. F=force p= density g=gravity a= area d= distance The Attempt at...
36. ### Finding Hydrostatic Force on the Plate

Before I begin I would like to say hello to everyone. This is my first post. I will follow and abide by all rules here. Homework Statement A rectangular plate measuring 2m by 5m is suspended vertically in a liquid with density 500 kg per cubic meter in such a way that one of its longer sides is...
37. ### Hydrostatic Force on a submerged dome

Homework Statement A half-spherical dome of radius R is submerged at a depth H underwater. Find the hydrostatic force acting on the dome. Homework Equations The Attempt at a Solution
38. ### Find the total hydrostatic force on the face of a semi-circular dam

Homework Statement Find the total hydrostatic force on the face of a semi-circular dam with radius of 20 m, when its reservoir is full of water. The diameter of the semicircle is the top of the dam. Homework Equations The Attempt at a Solution the width at any point would be...
39. ### Hydrostatic force on a semicircular wall

Homework Statement This isn't really a homework problem, it's a passage in the lecture notes that I don't quite get wholly. So here's the passage: "To compute the hydrostatic force on a semicircular wall of radius a which forms the end of a swimming pool filled with water, between D(y) = 0 and...
40. ### Calculating the Hydrostatic Force on the wall of a Cylindrical Tank

How would I go about calculating the hydrostatic force on the walls of an upright Cylindrical Tank. To keep it simple, it is completely full of water, is 1m tall, has a diameter of 1m. Many thanks for anyone that can help.
41. ### Calculating Hydrostatic Force of a Submerged Semicircle

Homework Statement There is a semicircle submerged in the water. The distance between the surface and the top of the semicircle is 2 ft, and the radius is 5 ft. Find the hydrostatic force. The answer is 1.2 * 10^4 N. Homework Equations y = sqrt(25 - x2) The Attempt at a Solution...
42. ### Hydrostatic Force Problem - Calculus

Homework Statement Find hydrostatic force on the vertical side of the tank that has the shape of the region bounded by the curves y=2x2, y=8. Assume that the tank is full of water. Homework Equations F=pgAd (force = density*gravity*area*depth)The Attempt at a Solution I know I need to set up...
43. ### Calculate Hydrostatic Force on 4x3 ft Triangle in 6 ft Tank

A tank that is filled 6 feet deep with water has a 4x3 foot, right triangular plate submerged into it so the 3 foot side is parallel to the bottom of the tank. The top of the triangle is one foot below the surface. Calculate the hydrostatic force on one of it's sides. The density of water is...
44. ### Hydrostatic Force (Out of my Calc book)

This is technically a physics problem but its straight outta my calculus book... The instructions are to express the force as an integral and evaluate it. My problem is just the initial set up. I've tried a couple of different ways and none of them get me the answer that I am seeing...
45. ### Hydrostatic Force and Center of a Mass - Calc 2

Hey guys, I have a couple of problems about hydrostatic force and center of a mass that I was hoping someone could help me out with. Center of mass Homework Statement Sketch the region bounded by the curves y=2x^3, x+y=3 and y=0. Find the coordinates of the centroid. Homework Equations Sorry I...
46. ### Hydrostatic force on submerged curved surface

Homework Statement Hi i know how to do these problems but its calculating the weight of the fluid, which you have to do to minus it from the vertical force. But in the solutions to the problem is say that the volume is R^2 - Pie *(R^2)/4 *1 The only thing i want to know is why is that...
47. ### Hydrostatic force acting on beam

Attached is the problem i am trying to get to grips with along with my current line of understanding, The column seen is a side section slice from the design of a water tank. The column is designed to take the load of the water. The column is designed with 2 unequal angle 75x50x6 steel...
48. ### Find the hydrostatic force exerted on a sphere

Homework Statement a spherical vessel is made by fitting together identical hemispherical halves across a horizontal plane.It is filled completely with water of weight W.What is the the resultant hydrostatic pressure force on the bottom half of the vessel? anyone please help me how to...
49. ### Hydrostatic Force: Impact on Sidewall and Bottom of Box

You have a rectangle box filled with a liquid to height H. How will the force on the sidewall of the box change if the height (H) is increased without adding anymore fluid? (i.e. a smaller solid box is added to displace the liquid). Assuming the equation F=specific weight*depth of center...
50. ### Hydrostatic force on a submerged object

Homework Statement Two large tanks are separated by a wall 20 cm thick, as shown in the figure below. One tank is filled with oil with ρoil = 876 kg/m3 and μoil = 0.45 Ns/m2. The other is filled with water with ρwater = 998 kg/m3 and μwater = 0.00100 Ns/m2. The depths of fluid in the two tanks...