Pond Definition and 50 Threads

  1. DaveC426913

    Sexing Winston the Chinese Pond Turtle

    I inherited a turtle of unknown provenance a few years back via my son's deceased gf. Its name is Winston and - with a little bit of sleuthing - I have determined it is a Chinese Pond Turtle AKA Reeve's Turtle. (Not my pic - taken from interwebz) It was brought to us being assumed by default...
  2. T

    Is it possible to run a pond filter using a solar panel?

    Hey is it possible to run a normal pond filter of a solar panel my pond is placed at the top of my garden and there's lots of sun around the pond i already have solar panel water fountain in there running with solar lighting to. The pond is to far away from the house to run cables down and I am...
  3. T

    Does Throwing an Object Overboard Affect Pond Water Level?

    I was asked this question: Assume you're sitting in a boat (you and the boat, together, are a mass M) which also contains a heavy object (of mass m). The boat (inc. you and the heavy object) is floating in a pond (a fixed body of water, rather than open sea). If you throw the object overboard...
  4. lola1227

    Ice pond with no friction -- how to get across?

    Would we use the mass of the bucket and pucks to get a higher acceleration? I don't understand the use of the pucks in this question? How would the three laws relate to this?
  5. T

    Can Fick's First Law Determine Diffusion Rate Without Surface Concentration?

    Trying to determine diffusion rate of a gas emitted from a body of water. I believe Fick's first law may apply: J = -D * (dc/dx) where: J = diffusion rate [mg/s×cm2] D = diffusivity constant (can be looked up based on type of gas and local air temperature) dc = change in concentration from...
  6. V

    Calculate lateral force/pressure of a body water

    So I'm planning to build an above ground concrete fish pond. The size of the inside of the pond will be (L)2000mm x (W)500mm x (D)500mm. What I want to know before I go any further is will the poured concrete walls hold the pressure of the water inside. So if I know the pressure of water I'll...
  7. M

    MHB Find the Border of a Pond with an Area of 800 sq. m.

    There is a pond in the garden having bank of equal with on all sides.If the area of the pond is 800 square meter then determine the border of the pond? please solve the math.
  8. lfdahl

    MHB Fish Pond Challenge: Show Equilibrium Variation with $R_f$

    Suppose a pond contains $x(t)$ fish at time $t$, and $x(t)$ changes according to the DE: \[\frac{\mathrm{d} x}{\mathrm{d} t} = x\left ( 1-\frac{x}{x_0} \right )-R_f\] where $x_0$ is the equilibrium amount with no fishing and $R_f > 0$ is the constant rate of removal due to fishing. Assume $x(0)...
  9. Joe Mc

    How to Build a Stable Retaining Wall for a Pond on a Sloped Property

    My name is Joe. I am 49 and have retired in the last year. I was not planning on this, and have had a hard time getting traction around the house. There are projects that I have had in mind and have dreamed about for years and now, I am finally able to get to them. The hobbies I once did that...
  10. W

    Volume of a Pond (Triple Integral)

    Homework Statement A circular pond with radius 1 metre and a maximum depth of 1 metre has the shape of a paraboloid, so that its depth z is z = x 2 + y 2 − 1. What is the total volume of the pond? How does this compare with the case where the pond has the same radius but has the shape of a...
  11. Charles CL

    Exit temperature of cooling pond

    Dear All, Referring to the subject above, I have found the calculation of heat load based on [Lawrence,K.W., Norman, C. P. & Yung, T. H. (2005). Advanced Air and Noise Pollution Control. Totowa: Humana Press.] My cooling pond system: 1. Purpose: cooling POME temperature from 70 to 40 degree C...
  12. A

    Settling the Debate: Air Compressors & Koi Ponds

    I wonder if someone can help settle a debate I am having over using air compressors to aerate garden koi ponds? A typical pond will have a small electric air pump (44W rated, delivers say 50 litres a minute at 1.5 metres deep in a 10000L pond) blowing air through a diffuser to add oxygen and...
  13. M

    Solving a Physics Problem: Boy & Girl on a Frozen Pond

    Homework Statement A 55-kg girl is standing near and to the left of a 75-kg boy on the frictionless surface of a frozen pond. The girl tosses a 1.8-kg ice ball to the girl with a horizontal speed of 7.5 m/s and he catches it. What are the velocities of the boy and the girl immediately after...
  14. L

    Does the weight of an object affect the speed of ripples in water?

    Do the speed of the ripples, or waves, in a pond depend on the weight of the pebble thrown into the water? I would think the answer is no since it should only depend on the properties of the water. Similarly if you take a rope and jerk it violently (more force) compared to softly (less force)...
  15. S

    Decay power and spent fuel pond

    Hello to all, i need more details about followings problems: Why nuclear spent fuel ponds must be cooling down and which is maximum allowable temperature in cooling agent? How we can evaluate decay power using theoretical formula?
  16. W

    Air absorbing moisture by blowing across pond

    Hi, Does anyone know how I can find out how much water the air can pick up by blowing across a pond? If the wind speed is 20m/s and the air has is 15 degree Celsius at the relative humidity level of 70% (absolute humidity of 9 g/m cube). How can I find out how long it would take to bring...
  17. O

    Explosion of firecracker on pond

    Homework Statement A firecracker (mtot = 0.70 kg), sitting on a frozen pond, explodes into three pieces, each of which moves horizontally. Piece 1 (m1 = 0.20 kg; v1 = 100 m/s) moves at a right angle to piece 2 (m2 = 0.20 kg; v2 = 125 m/s). What is the speed of the third piece? Homework...
  18. G

    Cooling a pond with river water?

    Cooling a pond with river water?? Hi all, this is kind of a basic question and I am looking for a simple formula to use to illustrate how an idea is not practical. I worked almost this exact same problem years ago in a limnology class but can’t remember how I did any of it. I help manage a...
  19. P

    Safe to remove inner wall of pond or will it burst?

    Safe to remove inner wall of pond or will it burst?? 1.Problem I have a fishpond. It is raised 0.4m above the ground, the wall being interlocking wooden blocks. The blocks are all locked together all the way round so they could be picked up and put down somewhere else. The pond is 2.4m long...
  20. B

    Why ice freezes on the top of a pond

    I'm having a little trouble understanding why water freezes on the top. Take this passage: We can use this unusual thermal expansion behavior of water to explain why a pond freezes slowly from the top down. When the atmospheric temperature drops from 7°Celsius to 6°Celsius, say, the water at...
  21. N

    How thick is the frozen layer of ice on top of a pond?

    Homework Statement The temperature at the bottom of a pond of depth L IS 4°C. The temperature of the air , just above the layer of ice frozen at the pond surface is -2°C. THE THERMAL CONDUCTIVITY OF ICE IS THREE TIMES THAT OF WATER The thickness(X) of the frozen layer of ice must be-...
  22. N

    How Does Ice Thickness Affect Heat Transfer in a Frozen Pond?

    The temperature at the bottom of a pond of depth L IS 4°C. The temperature of the air , just above the layer of ice frozen at the pond surface is -2°C. THE THERMAL CONDUCTIVITY OF ICE IS THREE TIMES THAT OF WATER The thickness of the frozen layer of ice must be-
  23. M

    What is the surface height of a still pond after an object is dropped in it?

    I had an idea for a project that would make use of a formula for the surface height of a body of water after an object was dropped in it. I wouldn't need a time-dependent equation, just a nice snapshot...although a general equation (a function of x, y, and t) would be nice. I haven't had much...
  24. E

    Equation help - water pressure at bottom of a pond

    equation help -- water pressure at bottom of a pond I'm trying to solve this problem "A car is flipped upside down in a pond, .50m below the surface, how much force is needed for the driver to push open the door." I got this wrong because the formula that was chose was F = (P - (P+rho x g x y))...
  25. P

    Calculating Pond Evaporation: Is Floating Glass a Good Idea?

    I have a fish pond which may have a slight leak. Or not - maybe the water is just evaporating. Searching it seems there is not simple way to calculate how fast water will evaporate. So suppose I put a glass beside my pond and measure how far the level of water in the glass has fallen in - say -...
  26. J

    Modeling Surface Water Temperature of a Pond

    Hi all, I am currently working on a task which requires a decent model of evaporation rates from a pond. Water is deposited into the pond from a series of nozzles that spray droplets into the air over the pond. I have found some equations that I would like to use that model evaporation rates...
  27. A

    Child walking across frozen pond (friction involved)

    Homework Statement A child stands on the surface of a frozen pond, 12m from the shore. If the coeff- of static friction between her boots and the ice is 0.05, determine the min. time req. for the child to walk to the shore without slipping. Homework Equations Ff = (u)(Fn)? The...
  28. H

    First ODE (dc/dt the rate of change of chemical in a pond)

    lets say there is a pond of 1,000,000 gallons of water. and the total of 10,000g of chemical is evenly dissolved in the water Fresh water starts pouring into the pond at the rate of 300 gallons/hour and the pond also releases water at the rate of 300 gallons/hour (hence no change in total...
  29. E

    Simple Diff EQ - Modeling the salt concentration of a pond

    Homework Statement The problem can be found here: http://alex.fangsoft.net/math.pdf I have completed Task #2, it is Task #1 that I am very lost on. Our teacher has really thrown us head first into the water with this one, I am very unfamiliar with differential equations and their...
  30. I

    Cannon at rest shot on frozen pond. what is cannon balls v after cannon recoil?

    A 253.5 kg cannon rests on a frozen pond. The cannon is loaded with a 6.8 kg cannon ball and is fired horizontally. If the cannon recoils to the right with a velocity of 6.9 m/sec , then what is the velocity (in m/s) of the cannonball just after it leaves the cannon? Also would like a hint...
  31. C

    Miser's Gold: A Frozen Pond Rescue Plan

    Homework Statement A miser sits alone in the middle of a frozen pond holding a bag of gold coins. He is unable to walk on the slippery ice. Explain how he could use the gold to rescue himself. Homework Equations Ft=change in p The Attempt at a Solution -i'm really not sure,but...
  32. V

    Overcoming Frozen Pond Friction with a Thrown Textbook

    Homework Statement A 680 N student stands in the middle of a frozen pond having a radius of 6.0 m. He is unable to get to the other side because of a lack of friction between his shoes and the ice. To overcome this difficulty, he throws his 2.6 kg physics textbook horizontally toward the...
  33. B

    Exploring the Analogy of a Pond to Understand Quantum Physics

    As a novice to Quantum physics and as a working physicist in the oil industry this may be a stupid question but I find the whole subject of quantum physics fascinating. I have been pondering the missing mass in the universe and particle vs wave argument and came across a nice description...
  34. M

    Need a formula to calculate BTU loss in a pond.

    I am looking at building an ortemental pond. The pond will be 15' x 3' with an average depth of 2'. I caculated it out to 673 gallons and 45 square feet of surface area. I plan to put tropical fish in it and will have to maintain a temperature of 72F year round. Worst case scenario would be an...
  35. DaveC426913

    How Can I Determine the RPM of My Pond Pump?

    I am building a small device that operates underwater so I am powering it from this...
  36. P

    Conservation of momentum and frozen pond

    Homework Statement A 730-N man stands in the middle of a frozen pond of radius 5m. He is unable to get to the shore of the pond because there's no friction between his shoes and the ice. So the man throws his 1.2kg textbook north horizontally at velocity of 5m/s. How long does it take him to...
  37. G

    Volume of water in a pond HELP

    Volume of water in a pond HELP! 1) A pond is approximately circular, with a diameter of 400 feet. Starting at the center, the depth of the water is measured every 25 feet and recorded in the table below. Feet from Center 0 25 50 75 100 125 150 175 200 Depth in Feet...
  38. L

    Finding Critical Angle: A Freshwater Pond Problem

    Homework Statement Hey, I’m a little bit confused on an optics question on how to find the critical angle when given the indices of refraction for two different mediums. The question deals with a laser beneath the surface of a freshwater pond. The indices of refraction are r=1.33 for the...
  39. M

    Calculate Water Temperature in Pond Receiving Hot Water: Formula Included

    I have an open water pond which will be receiving hot water (75oC) at a continuous steady rate. I want to know the temperature of the water leaving the pond at the other end. Is there a formula I can use to calculate this from the following information? Volume of pond (1650m3) (25mx25mx2m...
  40. M

    Pressure exerted by water in a pond

    I am trying to figure out how much pressure will water exert on the walls of the pond. The circular pond has a radius of 10 ft and depth of 2.5 ft. Pressure = density (water) * depth Pressure = 62.4 lb/ft3 * 2.5 ft = 156 lb/ft2 or 1.083 psi That will give me the maximum pressure which...
  41. DaveC426913

    Treating Green Algae in a Goldfish Pond: Visibility ~2 Inches

    How do I treat a goldfish pond green with algae? Visibility is ~2 inches. It's not the wall coating I'm concerned about, it's the water itself. I know how I'd treat it indoors - with a scraper and a water change, but that won't work in a pond. (Well, I suppose a water change would help...)...
  42. Evo

    Bitjumper's Amazing Swimming Pool to Pond Conversion

    Well, my friend bitjumper has an article about him In Better Homes and Gardens about a conversion he did from a plain old swimming pool to a beautiful pond. (Yeah he's the one that invited me to Germany ) Anyway, what he did was truly gutsy and turned out beautifully. Here are a couple of...
  43. T

    Volume of a lozenge shaped pond

    Hi all, First post here so 1) hello everyone, and 2) I have a problem that I am having trouble solving and was hoping to get some help from the folks on here. I am trying to work out the formula for calculating the volume of a lozenge-shaped pond. I think this is basically a problem...
  44. K

    Estimate the number of red fishes in the pond

    hi all! I have the following problem (in reality I study objects which may be perfectly described by "fishes" as below): Fishes in the pond: There are N fishes (x of blue color and y of red color) in the pond. N>>10^5, x+y=N, x>>y Each fish has a weight w - positive numerical value...
  45. R

    Circular Wave Equations: Pebble Dropped in a Pond

    What are the equation(s) for circular waves such as pebble dropped in a pond.
  46. P

    What is the Mystery Organism Seen in Pond Water?

    This has always made me wonder. My father got a microscope in WWII and I used it a lot when I was a kid. We had a pond out back and I spent many hours looking at drops of pond water through it but only saw this once. One time I saw something for a few seconds and never saw anything like it...
  47. T

    Where will the image of the fish appear in relation to the observer?

    Hi, This is undoubtedly an easy question, but I am having "one of those days"... A fish in a pond is 2m below the water's surface. An observing eye is 0.75m above the water and a horizontal distance of 1m from the fish. Given that the water has a refractive index of 1.33, where is the...
  48. C

    Fish Pond Population Growth: Is a Constant?

    Alright, my teacher the sadist gave us an assignment over the holidays, and so far, everyone in my class has gotten all but this. The equation is representative of the population growth of fish in a fish pond. p= m / 1+ae to the -kt p is the intial population, m the carrying capacity...
  49. recon

    Friction of a stone sliding on a pond

    This isn't really homework because I'm not doing it for school. I'm on my holidays at the moment, and I'm trying to do a bit of Physics on my own. As you can imagine, I have not gotten far, and am stuck on this problem: A stone slides in a straight line across a frozen pond. Given that the...
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