Underwater Definition and 154 Threads

Homework Statement Estimate the density of the water 5.3 km deep in the sea. (bulk modulus for water is B=2.0 *10^9 Homework Equations \DeltaV/V=(-1/B)*\DeltaP dP/dY=-\rhog The Attempt at a Solution I tried to use the equation: P=Po*e^(-\rhoo/Po)*gh But i kept getting ridiculously large...

Homework Statement The initial volume and depth of the gas bubble is V0 and H respectively. The bubble has a mass M and the gas can be assumed to be ideal. The gravitational field strength is a constant g. And the density of water is Dw. What then, is the time taken for a bubble initially at...

I'm after a dc waterproof water pump that can handle at least 60 feet of water, around 10 gallons a minute flow rate at 50 psi. finding this combination seems to be a real problem.any ideas?

If you poke at a soap bubble floating in air it pops. Can you make an underwater air bubble pop when you poke at it? I say no, my wife thinks you can. What say you? And why?

I have a question regarding the propagation of ferromagnetic materials via a coil gun or mass driver in an under water environment. Would the surrounding water effect the firing and or power of the shot. I know the water resistance is one thing to overcome. I was counting on using this more...

i understand that an object with smaller density than water will float on water with the same density, it will be submerged and "suspended" in the middle of the water my question is in the case of an object being denser than water, it will sink and finally touches the ground (underwater)...

Homework Statement A block of metal weighs 9N in air and 7N in water. What is volume of block? correct answer: 200cm^3 Homework Equations w=mg d=m/v The Attempt at a Solution I figured out that it has mass of 0.9kg on land...which may or may not be helpful.

Homework Statement A hollow sphere has average density of 3 g/cm^3 and a mass of 120g. What will the sphere weight under water? correct answer: 0.8 Homework Equations d=m/v w=mg The Attempt at a Solution I converted 120g into kg and then used w=mg to find weight on...

Lets say I will be operating a generator underwater in a "box" sitting on the river floor. Turbine blades will be spinning a rotor attached to said generator, and obviously the turbine blades are exposed to the water and the generator is sealed in the box. I'm having trouble identifying what...

Homework Statement The pressure exerted on an underwater vessel is 9.42 ATM. If the vessel is in fresh water, to what depth has the vessel descended? 2. Formula P=Po + pgh It is fresh water so p=1000 kg/m^3

Homework Statement http://img208.imageshack.us/img208/5158/29172992.jpg So we have some kind of pole floating in water. Area = A. Density = rho. At the bottom we have a point weight M. We want to calculate the normal tension inside the pole $\sigma$ at a position x. I have the...

Video at the link. http://www.timesonline.co.uk/tol/news/environment/article5936330.ece

A bodybuilder is holding a 20-kg steel barbell above her head. How much force would she have to exert if the barbell were lifted underwater?Fb= Density x Volume x Gravity Density= mass/volume 7860= 20/ V V= .00254 m^3 Fb= 1000 x .00245 x 9.81 Fb= 24.9174 N

Homework Statement "Provide a true explanation for what you see as you look at a lightbulb underwater" (See the attached Image) What you see: Out of water -> white opaque light bulb Underwater -> clear outside, opaque white inside Homework Equations N/A The Attempt at a...

Hi people, im new to this forum. I'm currently working on a underwater ROV for my school project. We did a experiment recently on the performance of our ROV. We met up with some problems on the motor & the propeller for the thrusting. The motor stalls just after 5secs. So I am thinking is...

Homework Statement A solid metal sphere of volume 1.05 m^3 is lowered to a depth in the ocean where the water pressure is equal to 1.38 x 10^7 N/m^2. The bulk modulus of the metal from which the sphere is made is 9.9 X 10^9 N/m^2 Given: The atmosphereic pressure is 1.013 10^5 Pa. What is...

Hey I've wanted to know why does the image of an object, which was put in water, seems to be larger than the real object, for a person, who sees it from outside the water. Thanks :smile:

hi! I have a question regarding work done lifting an object vertically upwards, under water. I am aware that work is done against hydrostatic pressure (which varies depending on a depth h from the surface), and that density of the fluid and the object may have a role in the calculation of...

[Solved] Total internal reflection, underwater light? Homework Statement A point source of light is at the bottom of a koi pond, at a depth of 0.525 meters. What is the radius of the circle of light formed on the water's surface? Take the index of refraction of water to be 1.33. Hint: Some of...

So... let's say I wanted to drop a pipe on the ocean floor with a 6" inner diameter... which has a pretty strong vacuum in it... what general size/material do you suppose that would require... assume it is miles long. I guess you could keep the vacuum pipe inside of another pipe that does not...

Hi I have a problem beyond my scope. I am not a lerned physics chap so please, any answers would be great if kept simple :) I have a pipe containing 300 litres of water. The pipe is 346mm diameter and 1 meter long. The top edge of the pipe is 1200mm under the sea. The pipe lies...

Homework Statement A ball of which radius is 15 inches is put into water and it sinks 2.5 inches. How much is the work done when it's pushed halfway under water? Homework Equations Air pressure doesn't have to be taken into account (not sure about that but that one I can do myself anyways)...

hi guys I am new here. for my final year physics assignment i am testing how colors are absorbed under water at different depths. i am planning to go scuba diving and take photos of a color spectrum at certain depths as was wondering if anyone here new much about this and would be able to...

[SOLVED] Kinematics: Average Deceleration Underwater Hello! First poster here. :cool: Here is a tough question from my online HW: Homework Statement A person jumps off a diving board 5.0 m above the water's surface into a deep pool. The person’s downward motion stops 1.6 m below the...

This has intrigued me, mainly because a lot of the scientists that go and see it for themselves change their mind and end up thinking that it is not a natural formation. It is an absolutely huge stone monument off the coast of Japan, and it has right angle sides, parrallel ledges, steps, and...

[SOLVED] Comparison of sound waves in air and underwater Homework Statement In air, the human ear is most sensitive to sound waves of 3300Hz. The auditory canal is part of the human ear. It is a tube of length 0.025m, i.e. 1/4 the wavelength of sound with frequency 3300Hz. When under...

Suppose I connect 2 9v batteries (for example) in series with a fish tank (30mm x 30mm x 20mm) containing water and an ammeter, is the current registered the same as the current in the water? I should think so but I am not sure. The copper wires-cum-electrode being positioned at either ends...

Would be grateful for a formula for the power required (theoretically) to move air down to a specified depth underwater. Metric if possible please. My calculations seem an order of magnitude too low.

http://en.wikipedia.org/wiki/Armadillidium_vulgare they are terrestrial crustaceans, but they have gills, i know this might be kind of a stupid topic but could it be practical and it be possible to select the bugs with better gills then the rest, have them breed with each other, so on and so...

Let's say that you're deep under the surface of the water in a submarine type thing. There is a hatch on the top. Let's say that the absolute pressure on the top of the hatch was calculated to be 2 atm. Inside the vessel, the pressure is only 1 atm. Someone is inside the vessel and...

If I have two rubber coated kevlar balls, one is filled with air and the other has a gas like helium in it, if submerged underwater, would the ball with helium be harder to keep underwater than the air filled ball would be, or would they be equal in their buoyancy? Also is helium easier to...

Math isn't a strong point of mine, and hope someone could give me a valid response to this. I'm still working on underwater physics, and have two questions. First, if I had a 34 oz coffee can that I want to submerge below water to a depth of 8 feet, how many pounds would it take to get the can...

Homework Statement While exploring a sunken ocean liner, the principal research found the absolute pressure on the robot observation submarine at the level of the ship to be 413 atmospheres. The density of the surrounding saltwater was 1025kg/m^3. Calculate the gauge pressure on the sunken...

When an item is submerged underwater, I believe that pressure from the surrounding water is equal in pressure around the item except from beneath, is this correct?

I always used to swim underwater but one day, I saw someone standing by their hands underwater, so I closed my nose by my hands and copied him. Since then, I can only swim underwater closing my nose w/ my hands, but then again, I need both of my hands to swim. So, I actually can't swim...

Hello, There are two bricks underwater. Brick A is closer to the surface and Brick B is further down below. Which Brick would be hardest to keep in place? I said Brick B becuase there is more pressure (H20) on it forcing it down + gravity. Brick A just has gravity and a little bit...

will someone who has google Earth please go to 1 deg 55'24.90"N 157 deg 21'52.47"W at an altitude around 100 miles Do you see an underwater mountain the exact same size and shape as the island next to it? the two foot print shapes could be where god stood when he created the earth, but...

What's an animal that can swim underwater, run on land, and fly in the air? Mythological or not. Just curious :smile:

Andre, mentioned floods in another thread, my interest has been kindled by a program on tv about Malta and under water ,"cart tracks", that may date human civilization 1000s of years older than is previously thought, giving some weight to a massive flood event in pre history, what are...

Can anyone give me an explanation of why a marble dropped into a swimming pool will fall faster than if you drop a marble into a water filled tube with a diameter only slightly larger than the marble itself (presume it doesn't touch the walls of the tube). It's something to do with how quickly...

"...It is true that down there at heart of the sea, are structures that sometimes have dimensions of several hundreds meters that are unusual, for which we we do not have a simple, direct explanation... " "...rocks appear. Some of them are not typical of Cuba. This leads one to think of two...

http://www.cyberspaceorbit.com/phikent/japan/japan2.html http://www.aliensthetruth.com/Worldmyst.php?ID=27 http://www.lightnet.co.uk/informer/civilisations/japan.htm Are these really pyramids underwater? What do you think

Hey this may be a stupid question but here goes... If you're underwater, say in a pool or something, and someone shines a light into the water will you see a color change? Why or why not?

I guess my real question is: does the depth of the water make any difference or do i assume it's constant pressure? If i can't make that assumption, how do i calculate the pressure the water has on this? The obvious answer is that if it's to the nearest tenth of a cm3, it's still coming out...

Hey I'm hoping there are some people involved in marine acoustics here :) I was hoping that someone here could maybe recommend some good books or sites that exaplain the use of transducers in Marine Acousitcs. I just need to have an idea of what sort of transducer I'm looking at. The carrier...

-----A bodybuilder is holding a 29.9kg steel barbell above her head. How much force would she have to exert if the barbell were lifted underwater?---- Ok...I'm really not sure of this one. I thought maybe the answer was the weight of the barbell (mg) plus the atmospheric pressure at sea...

would there be an upthrust or not if a perfectly smooth object was on a perfectly smooth ocean floor? I expect that since there is no water beneath the object there is no pressure to provide an upthrust, there would only be pressure above the object creating a downward force!?

I have a question i know it has something to do with refraction but uh... why do we need to wear goggles underwater to see straight>??

"Sea-gypsy Children": Human underwater sight secrets revealed http://www.sciencenews.org/articles/20030517/fob4.asp

When I go swimming (or rather walk in the water; I can't swim but I can pretend :redface: ), I like to try to swim under water and when I try, I can't. Why? Because I only stay under for a few seconds and float right back up again. I took a swimming class once, and the teacher couldn't figure...