Loess (US: , UK: ; from German Löss [lœs]) is a clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of the Earth's land area is covered by loess or similar deposits.Loess is an aeolian (windborne) sediment being an accumulation of: twenty percent or less clay and the balance mainly equal parts sand and silt typically from 20 to 50 micrometers per particle often loosely cemented by calcium carbonate. It is usually homogeneous and highly porous and is traversed by vertical capillaries that permit the sediment to fracture and form vertical bluffs.
Hi all. I am wondering how long it takes for heat to leave building.
This is the example I have been working on:
A building is 203m^3 and we want to raise temp from 10C to 21.3C.
Vol=203m^3 => mass = 244kg (density may not be completely correct but doesn't matter)
Cp=1.005 kJ/kg.k
Q...
Homework Statement
A ball of mass m = 1.9 kg moving with a speed of v0 = 20.1 m/s strikes an identical ball which was initially at rest. After the collision, the incoming ball (ball 1) goes off at q1 = 26° relative to its original direction and the struck ball (ball 2) moves off at q2 = 36° as...
hello,
i keep getting conflicting information on these and it confuses me
1) First my book says "In series circuit the voltage supplied by the cell is "shared" between all the components, so the more bulbs you add to a series circuit the dimmer they all become."
If you have a circuit...
If you have a continuous supply of water from a city main averaging 80 psi flow, will friction loss in a fire hose or pipe ever prevent water from flowing out of an opening downstream, assuming there is no elevation gain to overcome?
Some friction loss calculations state that EVENTUALLY the...
I'm creating a project where I am attempting to melt solder paste using the current running through two copper wires, in a kind of lap joint. I'm trying to figure out how much current would actually be going through the wires if I use a 9V battery. I'm not sure where to take into account heat...
i doing the solar system design.
seem like everything is on track now,
but just the cable loss i not really know how to calculate,
can anyone help me.
i has formula on this
(resistance on the cable (Ω/km)x length of the cable(L) x current of the solar panel(A)).
for the equation above , is...
I'm doing the solar system design now .
so far seem like everything is on track,
but now i face a problem on the DC cable loss.
is that has any formula to calculate the dc cable loss,
i has using this formula is
(losses of the cable (Ω/km)x length X current produce by the solar panel...
Griffith's Problem 2.40 (a) and (b)
Suppose the plates of a parallel-plate capacitor move closer together by an infinitesimal distance ε, as a result of their mutual attraction.
a) Use
P= \frac{\epsilon_0}{2}E^2
to express the amount of work done by the electrostatic forces, in terms of...
Please redirect me to the appropriate forum if I have posted in the wrong place...
This stuff is FAR over my head, and I need somebody with some real knowledge of thermodynamics and heat flow...
I own a scuba dive shop and of course we compress air to very high pressure, on the order of 300...
Greetings! I locate buried water pipe leaks (simplyleakdetection.biz) however attempting to approach more mathematically. I often isolate the leaking pipe and insert air pressure at one end. The leak is represented by the pressure drop rate as viewed on the air gauge when isolated from the...
I've been reading over Balanis' Advanced Engineering Electromagnetics in an effort to teach myself a bit about Electromagnetism.
I've stumbled across a question (not one in the book) that I can't seem to wrap my head around.
If there's a lossy dielectric or medium, how does the reflection...
The hydro meter for my house sits on a pole at the front of my property (5.5 acres) approximetly 200 - 250ft from my house I can't give you the wire size that runs under ground.
My question is: Is there a loss of power in the distance from the meter to the house and would this result in my...
the photons emitted during the big bang, now detected as the CMBR, have been red-shifted by a very large degree due to the expansion of the universe since the BB, resulting in much lower photon energy now than when the photons were first emitted. (i hope i have that correct.)
since there is...
Heat or deformation cannot contribute to velocity here, as per the view of conservation on momentum. So how is it that momentum is conserved but kinetic energy is not given a perfectly inelastic collision?
The two masses stick together.
There is no intrinsic means of expressing lost due to...
Homework Statement
65 kW is to arrive at a town over two 0.100 ohm lines. Estimate how much power is saved if the voltage is stepped up from 120 V to 1200 V and then down again, rather than simply transmitting at 120V.
2. The attempt at a solution
First I want to find the power lost in...
I have an anaerobic digester with a volume of 2500 m^3 and internal temperature is 60°C. But, average outer temperature is 20°C. We can neglect the insulations, accept c= 1kcal/kg, and assume that the surface area of the reactor is 300 m^2. I can calculate the heat loss from e=m.c.deltaT..
Is...
I was recently going through electric machinery fundamentels by Stephen Chapman and noticed the graph of the core loss current. I need help in understanding the nature of the current graph plotted against time, like how its value stays constant for some fixed time then varies linearly.
Homework Statement
An 16m by 9.0m house is built on a concrete slab 20cm thick. What is the heat-loss rate through the floor if the interior is at 29°C while the ground is at 19°C?
Given:
Area = 16*9 = 144m^2
DeltaX = 20cm = 0.2m
DeltaT = 29-19 = 10°C
k = not given
H = ?
Homework...
Homework Statement
(a) Consider a 10-Mev proton in a cyclotron of radius .5m. Use the formula (F1) to calculate the rate of energy loss in eV/s due to radiation.
(b) Suppose that we tried to produce electrons with the same kinetic energy in a circular machine of the same radius. In this case...
Homework Statement
A 500 MeV beam is scattered by a carbon target at 60 degrees. What is the energy loss (\omega or \nu) of the quasi-elastic peak? Ignore binding effects.
The Attempt at a Solution
This assignment is due tomorrow but we have yet to cover this material in my nuclear...
Homework Statement
If a 15kg object is released from a height of 11.58m and the objects loss in energy is 302 J, determine its velocity as it enters the container (object is being dropped straight down into a container)
Assume g = 9.8m/s^2
m(object) = 15kg = w(object) = 147N
s = 11.58m
ΔE =...
Homework Statement
I am working on a simulated lab in which we have a single particle projectile launched at a target particle (located at the center of the circular chamber) of similar weight. Once the collision takes place, I record the time it takes for the scattered projectile to travel...
i receive 220v single phase supply at my home. i have 60w incandescent bulbs installed in 2 different rooms which keep blowing almost every week (just after turning on)...There is no loss of appliances since mcb at mains resets but i have to replace bulbs every time.
Is there a solution ...
Homework Statement
A particle of mass m_{1} and speed v_{1} collides with a second particle of mass m_{2} at rest. If the collision is perfectly inelastic what fraction of the kinetic energy is lost in the collision? Comment on your answer for the casses that m1 is much much smaller than m2...
I have a cylindrical pipe of internal diameter of around 5mm, say capped at one end with pressurised fluid flowing though the other opening. If I have holes at the wall of the pipe, am i able to calculate the pressure loss due to water squirting out through those side holes?
Hi everyone. i have done a CFD smulation in fluent for a turbulent pipe flow and have plotted static pressure against distance x. from the graph i get a straight negtive gradient. i have been told that you should compare the pressure loss to Blasius equation and Darcy equation. How do i compare...
Hey everyone, I could do with a hand checking my understanding of calculating the current loss in cables just to make sure I am doing it right.
First up, is power loss. From my understanding of ohms law and P=VI it is possible to calculate the power loss in cables by using the formula power...
Homework Statement
"Calculate the reflection loss when a beam of radiant energy passes through an empty quartz cell assuming the refractive index of quartz is 1.55"Homework Equations
I/I_i = ((n2-n1) / (n2+n1))^2The Attempt at a SolutionI'm taking the refractive index through the empty cell...
I'm using the app on my iPod that's for myfitnesspal. Great app to help count calories. Also, I'm doing the Zumba exercise program to help with the weight loss/tone up.
Any opinions on all of this??
Homework Statement
A 200m long copper wire, with cross section area of 1.5mm2, is connected with a 10Ω resistor in a series circuit, and the supply voltage is 50V.
Homework Equations
Find the power loss in the copper wire, when ρ=0.0175 Ωmm2/m
The Attempt at a Solution
R=*L/A...
Homework Statement
I need to estimate the energy loss of electrons before they reach a detector, but I am unsure how to do it. I think I am supposed to integrate the stopping power function over the total distance but I can't solve the equation...
Homework Equations
Stopping...
"Bernoulli Loss"
Hi,
I am reading a fluid dynamics paper about dissipation due to turbulence in the fluid causing "Bernoulli loss". What exactly is meant by this? The Bernoulli principle concerns energy conservation. So, does Bernoulli loss simply refer to a loss of energy within the fluid...
I am working on a problem where I am heating a hollow cylinder from the outside with a NiCr wire which is then insulated. The pipe is cooled by running water through the center of the hollow pipe. I would like to find the heat flux transfer rate outward.
So my set up from the inside to the...
For minor losses, I read that the pressure drop is equal to the dynamic pressure * loss coefficient. However, in calculating dynamic pressure, it uses a single velocity. How do you determine this velocity when it will vary at the point of change in pipe diameter or direction? I have read...
I read this very interesting article on physorg about how planetary tilt is essential to life and various things that can diminish axial tilt over time or not give rise to one; things that would make life less probable.
But I came across this quote that I couldn't help but question the accuracy...
Googling for information on the topic leads me to graphs such as this, which suggest that if Beta and advance are optimal efficiency tops out at 85% or so. Some questions:
1) Is the ~15% lost energy converted to heat, or is there some stray kinetic energy in airflow that is somehow unusable as...
I know static friction can cause an object to accelerate, but also decelerate.
And i also know that static friction never cause energy loss, but I wonder when it causes an object to decelerate, its kinetic energy should decrease, so where is the mechanical energy gone? Has static friction done...
Hi all,
I have calculated the expected heat loss (fabric not ventilation) of a room in a house using Q=Ʃ(UAΔT) for each building element (window, door, wall, ceiling etc) making the room. The units are Watts.
How can I measure the actual observed heat loss of the room? I am currently...
I just want to confirm an error I have seen on another website about discharging of batteries.
The poster suggested that the mass of a battery decreases because matter is being converted into energy according to the equation E=mc2 as the battery discharges. They said that because c is so large...
how we doing i found the following information regarding finding the pressure drop in a pipe due to 90° bends. i was wondering could this be adapted for say a bend of 60° or 45°. what would be needed to change to the below information to allow this to happen?? thanking ou in advance. this would...
Using past results and Harkness ratings, Elo observed that the distribution of individual performances resembles a normal distribution"
http://www.chessbase.com/newsprint.asp?newsid=4326
What exactly is this "performance"?
Here's a question I posted about 10 years ago as a member of the forum. No one seemed to provide a satisfactory answer then so maybe someone might have some ideas on the subject:
When a permanent magnet attracts an object it does work and loses energy.
When the object is pulled away is the...
If I understand correctly, Hawking Radiation is created when the anti-particle of a virtual particle pair falls into a black hole while the particle of the pair escapes. The anti-particle goes on to annihilate with a particle in the black hole. Is not the annihilated particle identical to the...
Hello,
I am trying to calculate the heat loss of a capsule (mini submarine), size is 6m long and 0.5m radius of the ends and a height of 3m. I found a formula for calculating heat loss but it requires an R-value which I don't have, H = A(Thot-Tcold)/R (I'm guessing this is for insulated...
Hello all,
I'm not sure if any of you have ever used a device that measures RF transmission line loss and presents it as a graph of Insertion Loss (dB) vs. Frequency (GHz), but that is exactly what I'm trying to calculate. I've been looking through equations for days, and I just don't...
Homework Statement
Homework Equations
H=-k A \frac{\Delta T}{\Delta x}
kconcrete = 1.0 W / m K (approx)
The Attempt at a Solution
H=\frac{-1.0 (8 * 12) (10-20)}{0.23} = 4.17 kW
My problem is that the book (Essential University Physics, Wolfson) has the answer as -4.17 kW, but...
Homework Statement
I am working on a energy analysis in a supermarket. There is some open top display coolers, which is using a lot of energy - I don't have the opportunity to check excatly how much energy they use, so I have to calculate it. I don't have problems in calculating it when it is...
Hi,
On various websites I read that 70% of the heat loss of a pool is by evaporation, whereas up to 85% of the solar radiation can heat an uncovered pool.
We use 22mm thick black color EPE panels to cover our pool.
On a sunny day, is it better to cover the pool or to leave it uncovered ...
kinetic energy loss??
A 2850 kg car moving east at 8.0 m/s collides with a 3200 kg car moving east. The cars stick together and move east as a unit after the collision at a velocity of 4.86 m/s.
(a) Find the velocity of the 3200 kg car before the collision.
2.06 m/s to the east
(b) What...