Depth Definition and 340 Threads

Hey everyone, Im doing this research and reading this http://science.hq.nasa.gov/kids/imagers/ems/gamma.html" it had a diagram of the depth of penetration of different wavelengths into the eaths atmosphere... my question is, How come x-rays penetrate deeper than visible light - what is the...

Homework Statement Consider a submarine cruising 32 ft below the free surface of seawater whose density is 64 lbm / (ft^3). What is the increase in the pressure in psi exerted on the submarine when it dives to a depth of 172 ft below the free surface? Assume that the acceleration due to...

Homework Statement Calculate depth below the water surface of the centre of pressure of the water pressure acting on the submerged triangular lamina. The triangle is 2m below the surface and is shaped like this: Hypotenuse is sqrt(13) Other sides are 2 and 3, where the side with length 2 is...

Hello Forum, the formula for skin depth is both inversely proportional to conductivity and frequency omega. There seem to be 3 cases when the skin depth of a metal is exactly (or tends to) zero: 1) if an EM wave of frequency f (any frequency) is incident on a perfect metal wall (infinite...

Assignment due tomorrow & virus has deleted everything :cry: please help. AIM: To investigate the role of enzymes in the production of yoghurt from milk. I need full in depth information on the process of production in yoghurt.

Hello, i am reading on the Bohr Model. There are some parts i just do not understand. in classical mechanics, an object, such as an electron, revolving ina circle may assume an infinite number of values for its radius and velocity. Why is this? Therefore the angular momentum (L= mvr) (...

Homework Statement We know that 'g' decreases with height and the derivation for the formula is straight enough, but how is the formula for decrease of 'g' with depth derived? The Attempt at a Solution If an object is taken to a height 'h' above the surface of the Earth and...

Dear all I am slightly confused over the equations for skin depth. My university notes give me the equations: \delta = tan-1 (tan\delta) = \frac{\sigma}{\omega \epsilon} (loss tangent) where \delta is skin depth and \sigma is conductivity. I am also given the equation: \delta =...

Homework Statement I am a HS student researching the penetration depths of magnetic fields in conductors. Specifially, I am investigating the exponential decay of eddy currents induced within a conductor in the presence of a rapidly changing magnetic field. I am a bit confused as to why the...

Homework Statement A can of height h and cross-sectional Area Ao is initially full of water. A small hole of area A1<<Ao is cut in the bottom of the can. Find an expression for the time it takes all the water to drain from the Can. Hint: Call the water depth y use the continuity equation to...

Homework Statement a man stands by a swimming pool that is completley filled with water. his eyes are 1.8 meters directly above the edge and the pool is 12 meters wide. when he looks toward the corner on the opposite side of the pool , he estimates the pool to be 2.4 meters deep. if the...

In most books the amplitude does not change when water waves pass from deep to shallow water. In some books the diagrams show an increased amplitude. Which one is correct?

Homework Statement Hello to everybody I have this homework and my main issue is that is cannot find any bibliography to read that does what my homework requires. The problem goes like We have this recursive algorithm that calculates the sum of an array elements from array element k to array...

Homework Statement The problem is to find a well's depth Vo that the electron which is trapped inside has two stable states. Well starts at x=0 and ends at x=L. Homework Equations The Attempt at a Solution I tried to solve Schrödinger equation for each area (x<0 0<x<L x>L) but...

Homework Statement A glass tube of radius 0.80cm contains liquid mercury to a depth of 64.0cm at 12deg. Find the depth of the mercury column at 100 deg. Assume that the linear expansion coefficient of the glass is 10 X 10^-6 K-1 and the linear expansion coefficient of mercury is 0.61 X 10^-4...

I am building a home aquaculture system using air lift pumps. I have formulas for calculating water flow and for metering my cfm with orfices. My question is how does water depth effect air flow. I know that 1 psi = 27.68 inches of water. So my question is do I need to increase my psi...

Homework Statement A perfectly spherical golf ball with a specific gravity of 0.55 is dropped from a height of 10 m above the surface of a smooth lake. Determine the maximum depth to which the ball will sink. Neglect any frictional loses or energy transferred to the water during impact and...

Homework Statement There is a pool 5.50 meter wide filled to the top with water, A ray of light originates at the bottom left corner of the pool leaves the far upper right side at an angle of 14o. The question is asking for the depth of the pool Homework Equations...

Homework Statement A vertical cylindrical tank of cross-sectional area A_1 is open to the air at the top and contains water to a depth h_0. A worker accidentally pokes a hole of area A_2 in the bottom of the tank. Derive an equation for the depth of the water as a function of time t after...

Homework Statement A large aquarium of height 5.00m is filled with fresh water to a depth of 2.00m. One wall of the aquarium consists of thick plastic of 8.00m wide. By how much does the total force on that wall increase if the aquarium is next filled to a depth of 4.00m. D= density...

Homework Statement By what percentage does the density of water increase at a depth of 3.7 km below the surface? (change in p/p)Homework Equations P = pgh where p = density p of water = 1000 kg/m cubed h = 3.7 km = 3700 m bulk modulus of water (b) = 2 e 9The Attempt at a Solution b = -...

Well, I had always thought that it's nicer to have multiple degrees and stuff to get into grad school, but the more I lurk around here, the more I see people recommending additional mathematics courses and in-depth physics courses beyond the normal curriculum. Currently, I think I'll be...

What are some examples of pressure and depth?

Hi all, I have this problem : A coin is dipped to the bottom of a water filled container made of an opaque material. Observed from the water surface, the depth of the coin appears to be 2 meters. Find the real depth ( R.I. of water = 1.33 ) Since angles are not given, how do I apply...

Homework Statement A fish is 80 cm below the surface of a pond. What is the apparent depth (in cm) when viewed from a position almost directly above the fish? (For water, n = 1.33.) Homework Equations Snell's law: n_1 sin \theta_1 = n_2 sin \theta_2 The Attempt at a Solution So...

Homework Statement Atmospheric pressure is 100 kPa and a depth of 1m in water is equivalent in pressure to 10 kPa. A jam tin, open end down, is forced under water until the water half fills the can. At this stage, how far beneath the surface is the can? (ans is 10 m) Homework...

Though this sounds silly in itself to ask, I would still ask it. Is there any animal or bird which lacks the ability of depth perception? How would the world look to humans if they didn't have the ability to perceive visual depth? I'm not a biology or science student. Therefore, please be...

Why is the speed of water waves dependent on the depth?

Ok. There are 2 universal beams. One is 500mm deep and the other one is 400mm deep. For both beams, the top and bottom flanges are 200mm wide x 10mm deep. [SPAN of the beams is not given] Questions is..If the maximum bending moment capacity of the 400mm deep universal beam is 200 kn.m. What...

A fathom is a method for measuring lengths, usually reserved for measuring the depth of water. A fathom is approximately 6 ft in length . Take the distance to the moon to be 250 000 miles, and use the approximation above to find the distance in fathoms . I try to solve : I fa =...

hi guys. i have the london penetration depth defined as \lambda_l = \sqrt{\frac{m^{**}}{4\pi n_{s} e^{2}}}. i'm trying to figure out the dimensionality of it...surely it must be a length, but i get [(Kg)(m^{3})(A^{-1}s^{-1})]^{0.5} in SI units. am i doing something wrong? cheers.

After all, many of you have probably read/experienced dozens of books/papers/articles about many subjects. Not just science, but social science, whatever cultures you happen to be interested in, and the communities you grew up in. And of course, most people you talk to will only appreciate your...

An air bubble has a volume of 1.75 cm3 when it is released by a submarine 125 m below the surface of a lake. What is the volume of the bubble when it reaches the surface? Assume that the temperature of the air in the bubble remains constant during ascent. P= a+h*g*density a=101325Pa...

1. One person wearing goggles and one person without goggles are standing at the side of a pool. Both see a coin on the bottom of the pool, and both jump into retrieve it. When they are underwater, the person without goggles sees the coin at a greater depth than it was when she was above the...

Hi I am trying to run a FRAP (fluorescence recovery after photo-bleaching) experiment but I am struggling a little bit. For those not exposed to the technique it involves, for example, bleaching a spot in a specimen that is fluorescing rendering that spot dark in contrast. I have two separate...

Say we define Depth of Field, DOF, as max de-focus allowed for decent Fraunhofer Pattern. Then what's the DOF of a (positive) lens with focal length f?

Hi everyone. What is the difference between the London penetration depth and the Josephson penetration depth? Both of them have to do with the penetration of a magnetic field into the superconductor as far as I can see...

Homework Statement A rectangular tank is filled with water 2 m deep. At the bottom of one side wall is a rectangular hatch 1 m high and 2 m wide that is hinged at the top of the hatch. a) Determine the force the water causes on the hatch. b) Find the torque caused by the water about the...

why does the increase of sound frequency will decrease the penetration depth? how can this related to diffraction of sound?? Is it because they can be easily reflected?? need answer desperately, thx

Homework Statement A bottle, full of air at atmospheric pressure, whose volume is 500 cubic centimeters, is sunken mouth downwards below the surface of a pond. How far must it be sunk for 100 cubic centimeters of water to run up into the bottle? Homework Equations The Attempt at a...

Homework Statement Hello! I am an honors physics student and i have been assigned a project that has puzzled me. I have a container full of sand, a couple meter sticks, a tennis ball, and a stopwatch. What I need to do is prove something through the use of these items. What I am going to try...

Sam is sitting in her fishing boat watching a trout swim below the surface. She guesses the apparent depth of the trout at 2.0m. She estimates that her eyes are about 1.0 m above the water's surface, and that the angle at which she's observing the trout is 45 degrees. a) draw a diagram to...

Homework Statement A swimming pool has dimensions 34.0 m 9.0 m and a flat bottom. When the pool is filled to a depth of 2.30 m with fresh water, what is the force caused by the water on the bottom? I have the answer to this which is 6.90 x 10^6, however I cannot figure out the pressure on the...

Area, volume and depth relation? Im given a object, which is a raingauge orifice. it has an area of a certain value. This object collects x amount of water. How do i find a depth from these given values? Is there a formula for calculating depth?

Homework Statement A penny is located at the bottom of a barrel of water 1m deep. There is a 20cm thick layer of oil on top of the water. To an observer at normal incidence, what is the apparent depth of the penny. n for water is 1.33, for oil it is 1.5 Homework Equations Snell's law...

Greetings, Kindly, may I have my answers checked, please. Homework Statement d. A 40kg child sits on a swing of length 8.0m and is swinging with a maximum displacement of 2.0m from the equilibrium position. If the motion can be considered to be SHM, calculate the: i. Period of...

We wish to determine the depth of a swimming pool filled with water without getting wet. We measure the width of the pool, which is 5.50m. We then note that the bottom edge is just visible when we stand and look at an angle of 14.0 degrees above the horizontal line. a)Calculate the depth of...

Let A be a matrix and \mu be an eigenvalue of that matrix. Suppose that for some k, \tex{ker}\left(A-\mu I\right)^k=\tex{ker}\left(A-\mu I\right)^{k+1}. Then show that \tex{ker}\left(A-\mu I\right)^{k+r}=\tex{ker}\left(A-\mu I\right)^{k+r+1} for all r\geq0.

Any help how to approach this problem. The depth of pond is 10m. What is the apparent depth for a person looking normally to the water surface? ( Refractive index )water =4/3.

Hey ya, Well, I have been having a difficult time finding the answer to this question, probably because I don't know the specific terminology. So here I am. I did not know exactly which forum category to put this in so... I am building a small diving bell with a remote controlled camer...