Depth Definition and 363 Threads

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

What is optical depth? I have searched everywhere but I can't find any satisfying answer. It's stated often with radiative transfer that its the integral of the absorption coefficient for a certain distance. You usually distinguish between optical thin (tau <= 1) meaning you can 'see' through...

Homework Statement A swimming pool is 5 m wide, 10 m long, 1 m deep at the shallow end, and 3 m deep at its deepest point. A cross-section is shown in the figure. If the poole is being filled at a rate of 0.1 m^3 per minute, how fast is the water level rising when the depth at the deepest...

penetration depth??! How would I find the penetration depth of a staple shot into a material by a staple gun. It doesn't have to be specific to a staple. Material I am concerned with is pvc. Even a general approach is fine. I know the force opposing the staple going in is the friction of the...

Penetration depth? How would I find the penetration depth of a staple shot into a material by a staple gun. It doesn't have to be specific to a staple. Material I am concerned with is pvc. Even a general approach is fine. I know the force opposing the staple going in is the friction of...

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...

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...

A plane mirror is placed on the level bottom of a swimming pool, which holds water to a depth of 3 m. A swimmer is located 2.0 m above the mirror. An observer above the water looks vertically downward at the swimmer and its image in the mirror. What is the apparent difference in depth between...

Homework Statement I have tried this problem six times and it's still wrong. The problem is A research submarine has a 22.8-cm-diameter window 7.9 cm thick. The manufacturer says the window can withstand forces up to 1280000 N. What is the submarine’s maximum safe depth? The pressure...

if I want to calculate the pressure at a given depth in the ocean or a lake 1 atmosphere of pressure will support a column of water 32 feet high right? so if the lake is 20,000 feet deep can we just divide 20,000 by 32 and get 625 atmospheres at the depth? i see that the...

Homework Statement 'Briefly explain the importance of skin depth in the context of radio communications.' Homework Equations The Attempt at a Solution A guess would be that, the frequencies of the radio transmissions should be kept small so that the signal has a large skin depth...

I placed a cellphone in 2 half-spheres that i closed afterwards to create a metal cavity (aliminium 1mm) and called it (with another cellphone). The phone rang even if it wasn't supposed to considering the skin effect (wavelenght were about 0,04m and i couldn't see any holes). Anyone has a clue why?

A stone is dropped into a well. The sound of the splash is heard 3.96 s later. What is the depth of the well?

I have trouble understanding why water waves tend to speed up for waters deeper than 1/2 wavelength and slow down for waters shallower. I have read it has something to do with how the particle orbit changes to elliptical in shallow waters. Why does the particle orbit become a flat ellipse in...

Homework Statement A 1.6 m long glass tube closed at one end is weighted and lowered to the bottom of a freshwater lake. When the tube is recovered, an indicator mark shows that water rose to within 0.32 m of the closed end. Assume the temperature is constant, the acceleration of gravity...

Homework Statement A 7.00 g bullet, when fired from a gun into a 1.00 kg block of wood held in a vise, penetrates the block to a depth of 7.40 cm. This block of wood is next placed on a frictionless horizontal surface, and a second 7.00 g bullet is fired from the gun into the block. To what...

hi there, I am stuck on this question can some give me a hint on how to solve the question: the question is: Calculate the skin depth for copper at 1.0 GHz . σ = 5.8x10^7 S/m, εr=1, μr=1. the formula i think that i need to use is tan δ = σ / (ω)(ε0)(εr) ω = 2nf = 2 x n x 1 x 10^9...

Homework Statement A small logo is embedded in a thick block of transparent material (n = 1.73), 3.59 cm beneath the top surface of the block. The block is put under water (n = 1.333), so there is 1.86 cm of water above the top surface of the block. The logo is viewed from directly above by...

Homework Statement A 4.0m wide swimming pool is filled to the top. The bottom of the pool becomes completely shaded in the afternoon when the sun is 20 degrees above the horizon. How deep is the pool? Homework Equations \theta = arcsin(n2/n1) n1sin\theta1= n2sin\theta2 The...

Homework Statement A stone is dropped into a well. The splash is heard 3 seconds later. What is the depth of the well? Homework Equations the change in t= change in length/ velocity of sound The Attempt at a Solution V= 343 m/s which is the speed of sound Ok I solved for...

Hey guys sorry my first post is a help request and not an introduction or anything but I'd really appreciate a helping hand here Homework Statement Show that the extinction A(λ) and optical depth τ(λ) are related by the linear relationship A(λ)=1.086*τ(λ) Homework Equations...

Homework Statement A stone is dropped from rest into a well. The sound of the splash is heard exactl 2.00 s later. Find the depth of the well if the air temperatrue is 10.0 degrees Celsius. Homework Equations Possibly the Kinematics Equation V= Vo sqrt(1+Temp/273) The Attempt at a...

Homework Statement Evaluate the net force on a 200 -m high dam with a 60 mwater depth. Homework Equations P=F/A p(hydrostatic pressure)=rhogh+patm The Attempt at a Solution The atmospheric pressure acts on both the dam and the water, so it cancels out of the equation. g=9.8m/s^2...

Question about "naked" swimming at great depth after pressurisation In the 1989 movie The Abyss, we see Ed Harris' character briefly swim without pressure suit (couldn't fit this into the title, hence the word 'naked') from one cabin to an other, several hundreds of meters below sea level...

Homework Statement In a vessel, a layer of benzene (n=1.50) 6 cm deep floats on water (n=1.33) 4 cm deep. Determine the apparent distance of the bottom of the vessel below the upper surface of the benzene when viewed vertically through air. Ans 7 cm Homework Equations Snell's law n sin...

Homework Statement A tube of length L = 25 m that is open at one end contains air at atmospheric pressure. This is done in Denver so atmospheric pressure P = .667 X (1.10 X 105 Pa). The tube is thrust vertically into a freshwater lake until water rises halfway up in the pipe. Find the depth...

Homework Statement A plane wave of 1 MHz frequency in free space is incident normally on a copper surface [\sigma=5.8*10^7, \mur=1, and \epsilonr=1]. If the magnetic field strength at the surface is 1 mA m-1, find the depth at which it is 2.5% of this value. Calculate the...

Homework Statement A 7.00 g bullet, when fired from a gun into a 1.00 kg block of wood held in a vise, penetrates the block to a depth of 7.60 cm. This block of wood is next placed on a frictionless horizontal surface, and a second 7.00 g bullet is fired from the gun into the block. To what...

Homework Statement A 2.1 m long glass tube that is closed at one end is weighted and lowered to the bottom of a freshwater lake. When the tube is recovered, an indicator mark shows that water rose to within 0.43 m of the closed end. Determine the depth of the lake. Assume constant temperature...

Homework Statement A research submarine has a 40.0 cm-diameter window 8.50 cm thick. The manufacturer says the window can withstand forces up to 1.20×10^6 N. What is the submarine's maximum safe depth? The Attempt at a Solution The area which force will be exerted on is A= Pai * r^2 =...

cavity on a water surface A vertical air jet from a straw produces a cavity on a water surface. What parameters determine the volume and depth of the cavity?

Homework Statement Although human beings have been able to fly hundreds of thousands of miles into outer space, getting inside the Earth has proven much more difficult. The deepest mines ever drilled are only about 10 miles deep. To illustrate the difficulties associated with such drilling...

Hi guys, I'm trying to find a reliable formula for calculating the depletion depth in a PIN diode at a given voltage and knowing the doping of the layers. Does anyone have one? Formulae for the PN diode are common, but don't apply to the PIN directly as far as I can see. I found a formula...

Hi, Excuse me for not putting this post on Academic Advise. I am a mechanical engineering student and therefore would like to target my question to the general ME audience who might have a better understanding of the field. I see myself as being an engineer working in the industry after my...

Homework Statement We have to do a project on finding out the relationship of velocity of the impact to crater depth by experimental methods, then we are supposed to find out the answer on the internet and compare it without experimental results. However, i couldn't find any website that wrote...