Coefficient Definition and 1000 Threads

I have been trying to calculate the transmission coefficient for a quantum tunelling case, but I seem to get the coefficient value more than 1. How is that possible? The equation i used is based on the wikipedia page (I am unable to link because I am underpost). Also typically what are...

Homework Statement Homework Equations I believe: F = m . a Ffriction = μs . N Ffriction = μs . mg . cosθ The Attempt at a Solution I don't quite get how the equations above would give me an answer to the minimum friction required so that the farmer doesn't slip. I know Fl =...

Homework Statement Calculate the coefficient of friction between the wooden block and the table top, using a pendulum to hit the block. Mass of pendulum weight = 1 kg Mass of wooden block (with weight on top) = 2.073 kg Release height of pendulum = .06 m Pendulum's distance from...

Homework Statement A prism has a mass of m = 80 g, and you wish to lift it, touching the upper two faces only. If the coecient of friction between the prism’s surface and your skin is  = 0:4, what is the minimum force that must be applied to each face? Homework Equations F=μR...

Homework Statement A 25.0 kg block is released from point A (on a ramp, think of a skateboarders half pipe) at 3.00 meters. The track is frictionless except from points B to C (which has a length of 6m). The block travels down the track from point A to B, at which point it hits the friction...

I don't understand what determines the coefficient of friction. Can someone explain it to me using examples?

I have a Mathematics C assignment, with one question being about static and dynamic friction. But I think it fits this forum. Anyway, we need to conduct experiments to show if there is a difference between static and dynamic friction or not with three different surfaces. The weight of the...

$$ \varphi(x) = A\cos x\sqrt{\lambda} + B\frac{\sin x\sqrt{\lambda}}{\sqrt{\lambda}} $$ $$ \text{B.C.} = \begin{cases} u(0,t) = u(L,t)\\u_x(0,t) = u_x(L,t)\end{cases} $$ Which leads to $$ A(1 - \cos L\sqrt{\lambda}) = B\frac{\sin L\sqrt{\lambda}}{\sqrt{\lambda}} \quad \text{and} \quad B(1 -...

Homework Statement A skier weighing 90kg starts from rest down a hill inclined at 17 degree. He skis down the hill and then coast for 70 m along level snow until he stops. Find the coefficient of kinetic friction between the skis and the snow. What velocity does the skier have at the bottom...

we know that the quantum well absorption coefficient is calculated by summing over the electron-heavy hole and electron-light hole transitions: α_{w}(E) = \sum_{n}α_{e_{n}-hh_{n}}(E) + \sum_{n}α_{e_{n}-lh_{n}}(E) where n is the n^{th} transistion. but when the photon flux is incident...

Homework Statement I've been given the mission to find out the drag coefficient for the Ahmed Body. The drag coefficient itself it too hard to measure. The problem for me is to find a way to separate the drag coefficient to Pressure Drag coefficient and Skin friction coefficient. My question...

Homework Statement A 65-kg speed skater with a velocity of 15.0m/s comes into a turn on the track of radius 25.0m. a) How much friction must be exerted between the skates and the ice to negotiate the turn? b) Determine the coefficient of friction between the skates and the surface of...

Homework Statement One of the most popular rides at carnivals is the one that resembles a large circular drum that rotates on its axis. Once the ride is spinning fast enough, the floor drops down and the riders are left pinned to the inside wall of the drum (I believe they are describing a...

Homework Statement a bus passanger has her laptop sitting on the seat next to her while the bus moves at 10m/s, the bus goes around a turn with a radius of 25m. what is the coefficient of static friction in order to keep the laptop from sliding? Homework Equations The Attempt at...

Homework Statement Show that for two arbitrary conductors the coefficients of capacitance C12 and C21 are always equal. Hint: Consider a two-conductor system in which the two conductors have been charged so that their potentials are φ1f and φ2f respectively (f for ”final”). This condition...

Hey guys! Ok, so I don't have that much to work with, and I am sorry for my lack of detail, but my memory is a bit fuzzy. I had to do a problem like this for my physics test yesturday: On the test we were given a problem involving a roller coaster (Rotating Drum of Death was its name)...

Here is the problem: "A small package rests on the horizontal dashboard of a car. If μs = 0.333, what is the minimum acceleration of the car that will cause the package to slip off, assuming that the car is on a level road?" I really have no clue. Any equations I feel are relevant (μ...

Homework Statement A block begins to slide down a ramp after being elevated to an angle of 53.75 degrees. What is the coefficient of static friction? Homework Equations The Attempt at a Solution

Homework Statement When the mass M is at the position shown, it has a speed v0 = 2.17 m/s and is sliding down the inclined part of a slide. The mass reaches the bottom of the incline and then travels a distance S2 = 2.45 m along the horizontal part of the slide before stopping. The distance S1...

For a wave traveling from a medium with refractive index n1 to n2 with n2 > n1, the amplitude reflection coefficient is given by: r = (n2 - n1)/(n2 + n1) Consider a beam of light passing through a single pane of glass. There is a reflection at the front surface of the pane, with the...

[SIZE="6"] hey >>> my q is : how can i solve this ? http://hh7.an3m1.com/Sep/an3m1.com_e885c207f11.png

Homework Statement A block slides down a hill. The hill has a gentle 20° slope with respect to the horizontal. The block has an initial speed of 6 m/s. If the block comes to a stop after traveling a total distance of 11 m along the slope, what is the coefficient of kinetic friction between the...

So, we're trying to simulate an electric car running with a DC-engine. To get the calculations right we must determine the rolling resistance coefficient and airdrag coefficient. (We've already determined the rolling resistance to about 0.014, doing some linear calculations at low speeds <...

I'm trying to measure the coefficient of friction between a wheel that weighs about 4 grams and a ping pong table. Are there accurate spring scales I can use to measure the force it takes to move the wheel? I'm estimate the force required to move the wheel to be in the thousands POUNDS (.00xlb)

of restitution? i have no idea what it is and how it works...also please tell me about the line of impact and the line of tangent... in a semielastic collision ,how can we know the velocity of after collision ...

The Seebeck coefficient is the differential drop in voltage per unit temperature across a conductor. Goldsmid says that there must be a temp. gradient across a junction for a seebeck coefficeint to be defined. This makes sense if the difference in the fermi level energy between two dissimilar...

Homework Statement A grindstone in the shape of a solid disk with diameter 0.520m and a mass of 50.0kg is rotating at 800rev/min . You press an ax against the rim with a normal force of 160N, and the grindstone comes to rest in 8.50s . Find the coefficient of kinetic friction between the...

Hi everyone Homework Statement I'm looking for the molar absorption coefficient of Catechol but I can't find it anywhere. Can anyone help me out? I searched the internet as well as some books we have in our library, but I wasn't able to find it. Thanks for you help.

Homework Statement When the converyor belt was first installed safety checks were carried out to determine the limit of angle for safety. It was found that at an angle of 30 degrees the crates start to slip down. Calculate the coefficient of friction between the crates and the belt? (Diagram...

Hallo, does anybody knows where to get friction coefficients for different materials used in design (PTFE; PP; PVDF; PFA; TEFLON; VESPEL) or how to calculate them? Suppliers do not give a lot of data,..is there a theory behind to estimate friction coefficient? thanks in advance!

Homework Statement Calculate the frictional force, normal force and coefficient of friction for an 0.2kg object that is lying on a 35 degree incline. Homework Equations Ff= u x Fn F= m x a The Attempt at a Solution I managed to get FN= m x a x cos# = -9.81 x 0.2 x cos35 = 1.61...

Homework Statement A 2 kg. block is pulled up a 22° incline with a force of 10N parallel to the incline. What is μ_{}k if it moves up with constant speed? Homework Equations F_{}N = Normal Force f_{}k = μ_{}k F_{}N The Attempt at a Solution Forces perpendicular to plane...

I am running ANSYS fluent simulation flow over naca 0012 airfoil. So far the lift coefficient is similar with the published papers. The problem is drag coefficient is different so much in term of value compared to published papers. I have check my mesh quality and boundary condition, it shows...

i prepared a setup wherein i heat a nichrome wire with 3 volts battery, measure its power, the temperature of the nichrome and the temperature of air.. by using the formula ΔT=PRsurf where ΔT=Tnichrome - Tair P=VI Rsurf=1/hA, R is, basically, the thermal resistance to heat...

http://en.wikipedia.org/wiki/Drag_coefficient from wikipedia, it is written 1.98-2.05 for flat plate perpendicular to flow(2D) , but I have a differrent b/h ratio plate, where h=157mm and b=816mm , b/h=5.197 how to get the drag coefficient in this case? Thanks.

Homework Statement A potter's wheel having a radius 0.49 m and a moment of inertia of 10.6 kg · m2 is rotating freely at 52 rev/min. The potter can stop the wheel in 5.5 s by pressing a wet rag against the rim and exerting a radially inward force of 68 N. Find the effective coefficient of...

Homework Statement I'm working with a 0ne-dimensional random walk and looking at Fick's second law, below. All I've read seems to take D = 1/2 as a given for ordinary diffusion, but where does this come from? Is there a way to derive it? Homework Equations \frac{\partial } {{\partial...

I'm trying to model the flight of a small spherical object (such as a ping-pong ball) through air at smallish velocities (\approx 5{_{m/s}}) with linear drag so that F_{d}=-bv. The problem is, I can't find a table of linear drag coefficients (b) anywhere; it's always just the normal drag...

Homework Statement Prove the following: Let \rho be the correlation coefficient. Prove: \rho(X, Y) = 1 \iff P(Y=aX+b) = 1Homework Equations \rho(X, Y) = cov(X,Y)/\sigma_x\sigma_y The Attempt at a Solution I have no idea how to prove this, I know that rho must lie between 1 and -1 (inclusive)...

Homework Statement Determine the general solution of the system of homogeneous differential equations. The system of homogeneous differential equations is: X'_{1}(t) = 141x_{1}(t) - 44x_{2}(t) X'_{2}(t) = 468x_{1}(t) - 146_{2}(t) What is Eigenvalues of Coefficient Matrix? What is...

Homework Statement A truck weighing 15 tonnes is traveling down an decline of 15 degrees at 6.6m in 3s. He then stops and gets out. The truck then begins to roll down the decline as the brakes have failed. 1. What is the size of friction force acting on the rubber tyres of the charging vehicle...

Hello, I am looking at the following calculation for the reflection coefficient of a transmission line using the formula ((ZL - ZO) / (ZL +ZO) I can understand it all apart from the last part (0.355e^j). Can someone please tell me how that figure was gained from (-0.354 + 0.030j) (216 + j15...

Hi I know what pressure and friction drag are, I am having a hard time trying to find out how can you calculate the coefficient of drag for them? I think i have came across an equation for it: F_{D} = .5*ρ*v^{2}*A*C_{D} where F_{D} is the force of drag, ρ is density, v is velocity, A is the...

Consider the potential V(x) = \begin{cases} 0, & x < -a & (I) \\ +W, & -a < x < a & (II) \\ 0, & x > a & (III) \end{cases} for a particle coming in from the left (-\infty) with energy E (0 < E < W). Give the solution to the Schrodinger equation for I, II and III and use these to...

V(x) = |g| (δ(x+L)+δ(x-L) Consider scattering from a repulsive twin-delta function potential. Calculate R and T. I'm mostly confused about computing the T coefficients for multiple barriers. Would I compute the T coefficient for the barrier at x = -L and at x = L seperately? Then...

Homework Statement The coefficient of friction is to be found from a skateboard and rider rolling down a ramp, which has an angle of 5 degrees. The skateboard accelerates at .5308 m/s^2. The mass of the rider and skateboard is 91.3 kg, or 895 Newtons. The other data would be gravity...

Homework Statement Homework Equations SS(x-(mean x))(y- (mean y) f(x,y) dxdy (note: SS=integers for x and y) The Attempt at a Solution

Homework Statement A car can decelerate at -4.90 m/s^2 without skidding when coming to rest on a level road. What would its deceleration be if the road were inclined at 11° uphill? Assume the same static friction coefficient. Homework Equations Force of Static Friction / Normal Force...

Homework Statement I have an example were they determine the Cn coefficient for a Fourier series: My problem is i don't follow what happens in the following moment: neither am i sure how the two e^-inwt comes to be cos(nwt) in the last part. Homework Equations The Attempt...

When looking at rolling objects, the force of rolling resistance is determined by a coefficient of rolling friction. Is this coefficient constant for an object when both stationary and moving? Or is there a separate static and kinetic coefficient as there is with sliding friction? I am asking...