What is Hydrostatics: Definition and 74 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.

View More On Wikipedia.org
Recent contents Top users
  1. L

    Hydrostatics: solving for density.

    Homework Statement A block of wood floats in water with 2/3 of its volume submerged. In oil, it does so with 9/10 of it submerged. Find the density of the block of wood and the oil in terms of water's density. The Attempt at a Solution Setting the equilibrium condition (net force = 0)...
  2. K

    Physics homework on Hydrostatics

    Homework Statement 10% of a boat sink in water when it is float, from its total volume. 70% of its total volume sinks, when 1200kg loaded into it I) Calculate the mass of boat. II) The boat totally sink due to a hole in bottom of it, with that 1200kg load, with a uniform rate of 100kg of...
  3. L

    Calculating Pressure Difference in an Equilibrium Hydrostatics System

    Homework Statement See attached image. Two cylinders of the same diameter D contain the same incompressible (green) gas of density rho. Their bases are connected via a tube of diameter d containing an incompressible fluid of density rho m. The system is in equilibrium if the pressure on both...
  4. C

    Simple (I think) Hydrostatics Problem

    Being a rather novice engineer, I'm having trouble coming up with a solution to this problem. I think it's a rather simple problem with just a slightly complex twist (unsteady flow). There's a tank submerged in water a certain depth (pictured). The tank has a known volume and contain a known...
  5. M

    Hydrostatics - force on pistons in fluid

    Homework Statement Assume a cubical container with liquid filled in it and with one hole in each side in its four lateral faces with same cross-sectional area A. Now there are pistons covering these holes which keep the fluid inside it in equilibrium. If there is an increment of force F on...
  6. I

    Hydrostatics - Which point has higher pressure?

    Just a little question. Say a boat is floating on water. Imagine now two points in the shallow, flat sea floor. One is below the ship and the other is just water all the way up. Which point has higher pressure? I am imagining that both points have the same pressure due to the concept of...
  7. J

    Hydrostatics- need volume of submerged block- confused

    hydrostatics- bouyancy-need volume of submerged block- confused Homework Statement Need help with #11 attached tank has 2m of water gate is 1 m wide pulley is 1/2 m above water specific weight of concrete is 23.6 kN/m3 need to find volume of water to keep gate closed Homework...
  8. Saladsamurai

    Some Hydrostatics ConceptsWhen to use Buoyancy/When to use

    Alrighty- These questions are just to clarify some conceptual issues I am having. When finding the vertical force component exerted on a curved surface, we have used two major methods: 1.) Buoyant Force=wt of liquid displaced or 2.) F = the wt of the "missing liquid 'above' "...
  9. Saladsamurai

    Hydrostatics Problem Finding h

    Homework Statement So this is a five part problem. I have already done the first 4 parts that involved the mess of different liquids to the left in the diagram. I am only concerned with finding h now, which I believe does not even require me to look at the left hand side of the diagram. I...
  10. Saladsamurai

    Hydrostatics Problem (Why is this Wrong?)

    In calculating the vertical force component, you want to find the weight of the missing water. This should be simple: Find the Volume of the missing water and multiply by specific weight. Why is my volume calculation incorrect? I am using the volume of the rectangular prism whose top...
  11. C

    Hydrostatics - submerged lamina

    Homework Statement Calculate the depth below the water surface of the centre of pressure of the water pressure acting on the submerged triangular lamina, height 3m, base 2m and located at a depth of 1m below the surface.Homework Equations not entirely sureThe Attempt at a Solution I found the...
  12. L

    Hydrostatics and fluid mechanics

    Homework Statement A glass cube of length 2cm and specific gravity=3 is kept suspended via a spring balance and is kept exactly half immersed in water. surface tension of water is 75 dynes/cm. find the reading shown by the spring balance. (contact angle = 0 degree. g=1000cm/sec^2) i got...
  13. U

    Hydrostatics QA: Why Does Weight Increase When Adding Floating Material?

    Somewhere I happen to read that when some floating material is dropped in bucket full of water such that the water does not spill out, the weight of the total system increases. Well, but i don't understand why this should happen. the body floats as the buoyant force of water balances its...
  14. B

    Differences between the properties of the water hydrostatics

    hey, iv got an asignment to do n I am really stuck on this part could anyone help? The question is... Explain the properties of the water at rest behind the dam giving detail of how it exerts pressure on the dam. Also include details of any other properties you feel may be relevent. Explain...
  15. S

    Hydrostatics air volume exam problem

    exam help! Hydrostatics 1. Homework Statement A girl of mass 40 kg and volume of 40 liter wants to keep her head of volume 3 liter above water surface as she can't swim . how much air in Kg should she fill in her jacket?? 2. Homework Equations 3. The Attempt at a Solution mass...
  16. S

    How Much Air is Needed in a Jacket to Keep a Non-Swimmer's Head Above Water?

    Homework Statement A girl of mass 40 kg and volume of 40 liter wants to keep her head of volume 3 liter above water surface as she can't swim . how much air in Kg should she fill in her jacket?? Homework Equations The Attempt at a Solution mass of girl (m) = 40 kg volume of girl...
  17. A

    The Drinking Straw, Vacuum and Hydrostatics

    I am struggling with a mental model of what happens with the water level in a vertical pipe with the top end closed (say by a valve). Given: Pipe height = 5000 ft Pipe connected at bottom end to a chamber of pressure = 1000 psia water density = 62.4 lb/ft^3 Given a liquid full pipe...
  18. D

    Hydrostatics - pressure increases with depth

    Homework Statement i)Derive the fact that hydrostatic pressure increases linearly with depth under the surface of a fluid (assumed to be of constant density). Comment on how your answer would change if density is also allowed to vary with depth. ii) Show that the force per unit volume in a...
  19. M

    Bar in static equilibrium + hydrostatics

    Homework Statement A thin metal bar of length L is attached to a pivot point (point A in diagram). The bar is partially submerged in water and it can move freely around an axis that forms a 90 degree angle with the plane of the diagram. The density of the bar is 0.4 g cm^(-3). What...
  20. S

    Hydrostatics Relation for Seawater Pressure with Temperature Variation

    Homework Statement An empirical formula relating pressure and density for seawater w/ temperature constant is: p/pa = (k+1)(d/da)^7-k pa - pressure condition on the surface da - density condition on the surface k - dimensionless...
  21. K

    What Are the Key Principles of Hydrostatics and Buoyancy?

    Hi everyone, I am having some trouble understanding hydrostatics and buoyancy as taught in my textbook 1) "In a static fluid, the pressure is ISOTROPIC (same in all directions)" <----what does it mean by "same"? Same magnitude in all directions at a single point? Or same magnitude in the...
  22. C

    How Do You Calculate the Depth in This Hydrostatics Problem?

    Please HELP! Hydrostatics Problem Hi, I am really desperate and need help with the following problem in hydroststics. take a look at the picture: http://www.moncton.net/banners/statics.gif the answer is 0.955 meters. I have no idea how they arrived at that answer. Pleeeease HELP...
  23. T

    Having trouble with Hydrostatics problem

    Hi everyone! The problem statement reads: A 3.15kg piece of wood (Spec. Grav. = 0.5) floats on water. What is the minimum mass of lead, hung from it by a string will cause it to sink? Heres my reasoning. Since the log is floating, I know that it is in equilibrium, and therefore the Bouyant...
  24. A

    Solve Hydrostatics Problem & Draw FBD

    Hello, I'm currently trying to solve a problem involving hydrostatics, but I'm getting stuck when it comes to drawing the forces in the FBD. The original problem is here: http://img.villagephotos.com/p/2003-11/466966/hydrostatics.jpg This is my attempt at drawing the FBD...
Back
Top