# What is Submerged: Definition and 155 Discussions

A submerged forest is the in situ remains of trees (especially tree stumps) that lie submerged beneath a bay, sea, ocean, lake, or other body of water. These remains have usually been buried in mud, peat or sand for several thousand years before being uncovered by sea level change and erosion and have been preserved in the compacted sediment by the exclusion of oxygen. A forest can become submerged as the result of a lake or sea level rise that results in a lacustrine or marine transgression and in-place drowning of the forest. A submerged forest that lies beneath a lake can also be formed by the blockage of a river valley by either a landslide or manmade dam.

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1. ### Finding the weight of an object submerged in water

I have solved the question in the following way: The downward force is equal to the upward force. the upward force is equal to the weight of water displaced. If we find the weight of the water displaced then we will know the upward force. And since upward force is equal to downward force, we...
2. ### Electrolysis of Na2SO4 on Submerged Aluminum

Will Na2SO4 (Sodium sulfate), when used as an Electrolyte in Water, EAT away at submerged Aluminum components, when performing Electrolysis ?
3. ### Find Time to Reach Top of Beaker (10 cm)

Suppose I have a ball which is submerged in a fluid at height h0 The mass (m) is given The density of the fluid (ρw) is given The density of the object (ρo) and it's volume (4/3pi*r^2) are also given We can define all forces pushing the object downwards : Gravity m*g Ignore altitude...
4. ### A Betz Law & Submerged Turbines: Is it Applicable?

Hi, is Betz law fully applicable for hydro, hydrokinetic submerged turbines, since air is compressible but water is not ?
5. ### Force on submerged plate perpendicular to flow

Hey, I wonder how I can calculate the force of a plate that is submerged in water. I thought maybe the drag equation would be suitable for this with the drag coefficient set to 1.28 (https://www.grc.nasa.gov/www/k-12/airplane/shaped.html). But is implies the flow is according to the image...
6. ### Work done on moving a submerged object

I first worked out the buoyant force using rho = 1000, g = 9.8 and V = 1. (this gives Fb = 9800) I then worked out Fg of the tank (5 x 9.8 = 49) Then I used Fnet = Fb - Fg - T = 0 to work out tension as 9751. I thought the work done would be the work done by tension (9751 x 50.4), but I'm not...
7. ### How much of the wooden timber was submerged in water?

>Mass of a timber is $20 \ g$. And, density of that timber is $0.27 \ g/cc$. That timber was bind to a metallic materials and, it was released to $0.970 \ g/cc$ water. How much the wood was submerged in water? I was trying to solve the problem following way. $$F=Ah\rho g$$ $$=V\rho g$$ =V \...
8. ### Refraction of light question -- Flintglass submerged in oil

Hello, hopefully the question made sense, it was hard to translate. i attached a photo about the question. I started with n1=1.4, sinΘ1=37◦ and n2=1.62 1.4(sin(37◦))=1.62sinΘ2 1.4(sin(37◦))/1.62=sinΘ2 arcsin(0.52)=31.34◦ Is it calculated correctly?

10. ### Density of balls submerged in a liquid and connected by a hard rod

Performing force balance on the two balls, I obtain ## T+\frac{4\pi}{3}g \rho_3 R_1 ^3 = \frac{4\pi}{3}g \rho_1 R_1^3 ## ## T+\frac{4\pi}{3}g \rho_2 R_2^3 = \frac{4\pi}{3}g \rho_3 R_2^3 ## from which I obtain ## \rho_3 = \frac{\rho_1 R_1^3 + \rho_2R_2^3 }{R_1^3 + R_2 ^3 }## and ## 2T...
11. ### Resonant frequency of a pipe submerged under water

How do I calculate a resonate frequency of a length of pipe submerged totally under water? Do I just take speed of sound in water which is 1,481m/s at room temp, and decided it by length of pipe in meters multiplied by 4? so at 20 celsius water and 20cm pipe it would just be: 1481 / (.2 x...
12. ### I Which area should I use to calculate the force on a submerged surface?

Let's say we have a tank filled with water only half way up. I want to calculate the force being applied by the liquid on one of the walls, that's F = P.A. For the area (A), should I consider the area of the entire wall (H.L), or only the area of the wall that's in contact with the liquid...
13. ### Weight of fluids on a submerged person?

https://www.asi.edu.au/wp-content/uploads/2015/08/NQE_2009_Physics_solutions.pdf Pg 9 Q 11 A) Was wondering why there isn't a weight of water in the force diagram? The boy is submerged, as I understand. Do we normally include the weight of a fluid on someone or how does this work? For...
14. ### Depth to which the sphere is submerged

I draw a sketch of the diagram to the right. The body has a radius of ##r_B = 0.2## m. The volume of the body is given by ##V_B = \frac{4}{3}\times \pi \times 0.2^3 = 0.034\;\text{m}^3##. The mass of the body : ##w_B = \rho_B V_B = 400\times 0.034 = 13.37\,\text{kg}##. Hence the mass of the...
15. ### B Does Buoyancy Apply When Not Fully Submerged?

I am discussing with friends whether concept of buoyancy is applicable even if the full surface of body is not covered by fluid(s). As an example a clay ball is dropping in the pool water. Buoyancy is working on the ball. Then it reaches the pool flat and sticks with it to make a mountain...
16. ### Engineering Calculating Upthrust and Tension for a Submerged Pillar

Hello, Looking for help on the following: A crane is used to lower a vertical cylindrical pillar into a reservoir. The pillar has a mass of 4 tonnes and is submerged to a depth of 2.5m. It has a diameter of 1.1m. The specific gravity of fresh water is 1125kg/m^3, and 9.81m/s^2. Use a free...
17. ### EOM of simple pendulum submerged in a fluid

The question :- My attempt :- The confusion that I am having is that to get the required form of the equation of motion, I had to approximate ##\theta## to be small to get ##x=l\theta## so that I could get the acceleration and the velocity. But, I had to leave the ##sin(\theta)## in the...
18. ### Water level in a submerged closed vessel after it is turned upright

Hello all, I need Your help with one real / theoretical situation. We have submerged pipe filled with air at atmospheric pressure that is closed on both ends. The hole is formed on one pipeline end and the water starts flooding the pipe. Let's assume pipe is tilted somewhat and that no air...
19. ### Bouyancy Question: Two weights on strings, with one weight submerged

Hi new to the physics world and the symbiology is hard to understand completely. Attached is the work I've done to a final solution but I can't seem to get the answer in terms of only density of water and T1 and T2. Thank you for any assistance. [ Mentor Note -- Word file replaced with a...
20. ### Engineering Pressure Force on a partially submerged surface

Once I get the pressure, do I have to multiply times de area that is submerged (in this case it would be 25m^2), or do I take the whole area of the plate, including the part that is not submerged (in this case it would be 30 m^2) Thanks
21. ### Solar pool heating via a dark screen -- On the surface or submerged?

Summary: Looking for input on either floating or sinking a large sheet of dark screen for solar absorption in a pool Looking for input on either floating or sinking a large sheet of dark screen for solar heat absorption in a pool. My though its that screen would be very user friendly to roll...
22. ### Filling a long tube by submerging it in fluid

Hi everyone, I'm working on a first-year college assingment and need some help with it. I need to figure out how deep does a tube, initially filled with air, need to be submerged into water in order get fully filled, meaning in order for the air to be fully displaced by water. The tube is 1/2...
23. ### Pressure in Forces on Submerged Surfaces

Why does the pressure we take into account is the gage pressure and not the absolute pressure? Reading Fundamentals of Momentum Heat and Mass transfer by Welty in chapter 2 it says "the magnitude of the force on the element dA is PgdA ,where Pg is the gage pressure" my question is why the gage...
24. ### What Forces Affect the Rotation of a Submerged Disc?

1. A 20-lbf disc with diameter 18" and thickness of 3" is held static while completely submerged in water. Upon release of a lock, the disc experiences a torque from a torsional spring that causes rotation about its center of mass along the x/y axis (think coin toss, not wheel). If the spring is...
25. ### Pressure on a submerged object

New member: Stem cell biologist by training, and many years since my last physics class. Imagine I take a water balloon and fill it completely with water. I then submerge the balloon in a beaker of water and place the glass inside a sealed chamber. What forces are applied to the water balloon...
26. ### Air flow through a hole in a submerged pressure tank

Hello! I will try to formulate myself as clearly as possible, but english isn't my main language. I'm having trouble solving this problem that should be relatively easy to solve. Let's say we have a submerged pressure tank, constantly fed with air through a compressor, so it's maintained at a...
27. ### Writing: Input Wanted Submerged Structures in an Ocean World

Suppose that there exists a rotating water planet, i.e. a planet with a fairly deep ocean, which contains a large structure of a particular geometry submerged within the ocean. If this structure was assembled within the ocean will it, once it reaches a steady state, rotate at the same rate as...
28. ### Pressure on a vertical rectangular plate submerged in water

The question goes as follows..: A car driver has an accident and drives into a lake. The car sinks to the bottom. The distance from the car door to the water surface is 10m. The car door is 0.9m wide and 1.3m tall. Assume that the car door can be approximated as a vertical rectangular plate and...
29. ### Buoyant force on a submerged body

Homework Statement A hemispherical portion of radius R is removed from the bottom of a cylinder of radius R. The volume of the remaining cylinder is V and its mass is M. It is suspended by a string in a liquid of density ρ where it stays vertical. The upper surface of the cylinder is at a depth...
30. ### Find the weight of a partially submerged cylinder

Homework Statement Hello, there is a cylinder with cross sectional area 10cm2. The cylinder has a length of 50cm partially submerged in water and floats upright. Taking acceleration due to gravity as 10 m s-2 and the density of water to be 1000 kg m-3 Find the weight of the cylinder using...
31. ### How to calculate the weight of a submerged hollow cylinder?

A hollow cylinder (2 tons) is dipped in a chemical tank using hoist crane for treatment purpose. Can anyone please help me to show how to calculate the maximum weight of the submerged hollow cylinder when it is being pulled up because I need to choose the correct lifting capacity for the crane...
32. ### Force on the bottom of the vessel containing a submerged cube

Homework Statement Conside the fig below. A tank of water (height of water column b) is kept on a electronic weighing scale . a metal cube (side a and density D) is hung from a spring balance and the spring balance is slowly lowered into the tank till the cube reaches the bottom of tank. The...
33. ### Flow rate through a submerged orifice

Homework Statement Homework Equations Bernoulli: p1+½ρU12+ρgz1=p2+½ρU22+ρgz2 Continuity: Q=U1A1=U2A2 Area=CC*(¼πd2) The Attempt at a Solution [/B] I attempted to apply the Bernoulli equation, making point 1 the top surface of the left hand side and point 2 the instant at the sharp edge...
34. ### Calculating a Submerged Tank: Questions & Answers

Dear People I am busy with a tank that is submerged in water. The tank is mounted against concrete wall isolating the water. The tank is pressed against the wall due to the water pressure. When the tank is installed the water can be pumped away. The material used for the tank is stainless...
35. ### Fluid dynamics: half submerged straw opening

Homework Statement This is not a set question but a problem statement for an investigation. I am trying to understand the physics behind drinking through a straw, but not when the straw is fully submerged in the drink but at the end of the drink when the liquid and air both pass up the straw...
36. ### Hollow sphere half submerged in a liquid, find density

Homework Statement A hollow sphere of inner radius 9.0 cm and outer radius 10.0 cm floats half submerged in a liquid of specific gravity 0.80. (a) Calculate the density of the material of which the sphere is made. (b) What would be the density of a liquid in which the hollow sphere would just...
37. ### Block hanging from cord submerged in water, find density

Homework Statement A block hangs by a cord from a spring balance and is submerged in a liquid contained in a beaker. The beaker in turn rests on a kitchen scales. The mass of the beaker is 1 kg, the mass of the liquid is 1.5 kg. The spring balance read 2.5 kg and the kitchen scales reads 7.5...
38. ### Why Does Fluid Accelerate and Decelerate Over a Convex Surface?

Guys...Can anyone explain me why fluid accelerates and then decelerates when flowing over a convex surface and also concept of flow attachment in simple terms
39. ### Question: pressure inside an object submerged in water

I'm doing a question relating to the pressure inside on object submerged in water. Here is the question: A tube, height 1.2m, is submerged vertically in the ocean where the waters density is 10^3 kg/m^3. A diver initially holds the tube vertically directly on top of the water. He then dives to...
40. ### Fluid mechanics civil engineering

As shown in the attached image, a tank has an inclined wall at an angle of 450 to the horizontal. On this wall, there is a 1m square door that is hinged at A and has a simple latch at B. The distance between A and the free surface of sea water measured along the inclined wall is 2 m. (Specific...
41. ### Calculate Pressure & Speed of Submerged Water Jet 100mm Away

I am trying to calculate at what pressure and speed water from a high pressure water jet will hit an object 100 millimeters away from the nozzle opening, but i can't figure it out. The nozzle will be used at approximately 100 meter below sea level in salt water. Its a circular nozzle with a...
42. ### Loss of head at submerged discharge

Homework Statement in the notes , author said that the velocity within it is negligible? does the author mean the water velocity in the tank ? so the velocity (v^2)/2g in the 4.24 means the velocity in the pipe ? Homework EquationsThe Attempt at a Solution
43. ### Wooden Cube submerged length and the carry limit

Homework Statement A wooden cube with the length of 10 cm is and a density of 700 kg/m^3 is floating on water A)Find the submerged parts length of the cube B) find the maximum added mass to the block before it becomes totally submerged Homework Equations FB=density*volume*gravity FB=Fg...
44. ### Understanding Forces on Submerged Surfaces

Homework Statement i don't understand the statement 1 and 2 , can someone help to explain ? for 1 , does the author mean Fh= Fv ?? for 2 , does the author mean Fv = Fh + W ? but in statement 1 , Fh already = Fv Homework EquationsThe Attempt at a Solution
45. ### Hydrostatic forces on a submerged curved surface question

Hi, i would like to know how to do this question for fluid mechanics. Sorry as I am new i didnt know how to upload images so i just uploaded the image in justpaste, here is the link http://justpaste.it/pz7r
46. ### Finding volume of a submerged object

Homework Statement There is a block of wood floating on the surface of a body of water, with a ball attached to the bottom of the block by a string. I am asked to find the volume of the ball given the tension in the string. We also know the volume of the wood block from an earlier problem if...
47. ### What % volume of this floating object is submerged?

Homework Statement An object of 985 kg/cm^3 density is placed in water, which has a density of 1000 kg/m^3. What percentage of the object will be floating above the water? Homework EquationsThe Attempt at a Solution 985/1000 = .985, or 98.5%. 100 - 98.5 = 1.5%. Therefore: 1.5% of this object...
48. ### Density of bar submerged in water

Homework Statement A bar suspended in air weighs 1.75 N The same bar weigs only 1.4 N when suspended in water. Calculate; a. upthrust b. density of the bar Homework Equations D = m/v F = m*a The Attempt at a Solution a[/B]. Upthrust is 1.75 N - 1.4 N = 0.35 N b. Assuming density of water...
49. ### ASTM C127 submerged weight and SSD weight?

in ASTM C127 Aggregate test , why the weight of SSD is higher than water submerged weight?
50. ### Finding resultant force on a segment of submerged wall

Please see the attached image. I understand the area represents the resultant force per unit width. But I'm unsure what equation to come up with for the purple area. I'd appreciate a little patience here, it's been ages since I did this. Thanks