Coefficient Definition and 1000 Threads

Homework Statement A small block sits at the midpoint of a 2.0 m plank lying on a level floor. A student slowly raises one end of the plank until the block starts to slide. At that instant, the raised end is 0.55 m above the floor. Find the coefficient of static friction between block and...

Homework Statement A child pulls a friend on a sled. The child maintains a constant tension of 29.4 N in the rope. The combined mass of the friend and sled is 30.0 kg, and the coefficient of sliding friction between the sled and snow is 0.1. How far can the child pull her friend in 6 sec...

I am trying to design a heat exchanger for a stratified hot water tank which means that the heat transfer on that side of the exchanger will be totally dependent on free convection. I plan on using a shell and tube set-up but I have no idea on how to calculate the required mass flow rate from...

I am having my students do a lab to calculate the coefficient of static friction along a ramp. They are calculating the coefficient of static friction between felt and the table to be something like 0.40, yet when i did this lab, but along a horizontal surface, and not with a ramp, i get a...

Mod note: Moved from technical math section, so no template was used. Hey! So the complex Fourier transform of the square wave $$ f(x) = \begin{cases} 2 & x \in [0,2] \\ -1 & x \in [2,3] \\ \end{cases}, \space \space f(x+3) = f(x)$$ is ##C_k = \frac{3j}{2 \pi k}( e^{-j \frac{4 \pi k}{3}}...

Consider the following chemical equation: 2IO3-+wH2O2+xH+=>I2+yO2+zH2O Which of the following is the correct combination of the reaction coefficient y and z? A) 4&5 B) 5&4 C) 5&6 D) 6&5 How to obtain the answer? Thank you~

To simplify my question I would like to use a random example (although, the issue holds regardless of the numbers you pick). Suppose two objects collide (head-on) in one dimension. The initial parameters are as follows (units are irrelevant): m1=1;m2=2;u1=3;u2=-4; Also, suppose that exactly...

How do you prove that the maximum value of 2*cov(x,y) can be is equal to var(x) + var(y). Moreover, how do you prove that the correlation coefficient, cov(x,y)/(sigma(x)*sigma(y), can only be between -1 and 1.

How can I find an equation to calculate the lift coefficient on a basketball at different launch velocities? I looked at different papers explaining the physics of basketball throws but all i could find was an equation for the drag coefficient: -mv +1/2 ρ A Cd v^2 = mv

Homework Statement A force P acts as shown on a 200kg block placed on an inclined plane. The static coefficient of friction between the block and plane are Us= 0.5 . Determine the force of P to ensure he block is in the verge of moving down. The ans given is P = 560.4 N i have done in 2 ways...

Homework Statement why the µ for block is 0.3(between B and A) ? why can't be µ= 0.4( between B and C) ?? Homework EquationsThe Attempt at a Solution

Homework Statement An electric motor is used to pull a 125 kg box across a floor using a long cable. The tension in the cable is 350N and the box accelerates at 1.2m/s2 (forward) for 5.0s. The cable breaks and the box slows down and stops. Calculating the coefficient of kinetic force? Given...

Homework Statement y''+10y'+25y=x+2+3e-5*x Homework EquationsThe Attempt at a Solution F(D) = D2+10D+25 zeroes: -5 yc= C1*e-5*x + C2*e-5*x *x yp = ax+b + C*e-5*x yp = ax+b + C*e-5*x*x2 I just want to know if my yc and yp is correct, after that I know how to do it.

I have a long-standing puzzle about the Kubo formula of thermopower S=L_{21}/L_{11}. The electric conductivity (L_{11}) can be expressed in terms of real time current-current correlations. Similarly, the heat conductivity can be expressed in terms of real time correlations of heat currents...

Homework Statement What is the minimum coefficient of friction needed between the tires and the ground so you make the turn safely?[/B] Car= 1394.7kg You=75kg Radius of turn = 40m Velocity = 20m/s Homework Equations Fnet = MAc (Ac = centripetal Acceleration) = Force of friction Force of...

Homework Statement A 1000N crate is being pushes across a level floor at a constant speed by a force (F) of 300N at an angle of 20 degrees below the horizontal, what is the coefficient of kinetic force? Homework Equations Fk= uk*N uk= Fk/N[/B] Fk=F2 The Attempt at a Solution in the back of...

Homework Statement If a rubber ball is dropped from the height of 120 cm from the floor, and rebounds to a height of 80 cm, what is the value of e, the coefficient of restitution? Show your reasoning and justify your solution. initial distance 1= 120 cm final distance 1= 0 cm initial distance...

Homework Statement A horizontal force of 150 N is used to push a 50.0 kg packing crate a distance of 5.00 m on a rough horizontal surface. The acceleration of gravity is 9.81 m/s2 . If the crate moves with constant velocity, calculate: a) the work done by the force. Answer in units of J. b)...

The Joule coefficient, μJ, is defined as μ = (∂T/∂V)U. Show that μJ CV = p – αT/κ Relevant equations Cv=(∂U/∂T)v κT=-1/V*(∂V/∂p)T α=1/V*(∂V/∂T)p dV(T,p)=(∂V/∂T)pdt+(∂V/∂p)TdpWhat I have attempted was to make μ = (∂T/∂V)U=(∂T/∂U)V(∂U/∂V)T=(∂U/∂V)T*Cv-1. Then α/κT=(∂V/∂T)p/(∂V/∂p)T because the...

how can I interpret the condition "if sum of (xi-x_bar)^2(yj-y_bar)^2=0 when i=/=j?" why does this make the line linear?

Homework Statement A lab I've performed was measured using forces. As the mass increases, the force does as well. The inclined plane is at an angle of 30 degrees. Now, finding the coefficient, should the kinetic and static friction be decreasing on a plane? I've measured the frictions on a flat...

Question: The coefficient of restitution for ball colliding with steel is 0.95. If ball is dropped from height h sub o above steel plate, to what height will the ball rebound? Please help me with this one, Is there a formula for this? all I know is e equals velocity of the first object...

Homework Statement A car moving at 50mph coasts to a stop while traveling a distance of 150ft on level ground. what is the size of the friction force needed to bring this car to rest? Homework Equations vf^2 = vo^2 + 2a(xf-xo) F=ma Fk=un[/B] The Attempt at a Solution I first converted...

I've read that drag coefficient depends on the shape of the object but I am confused as to what shape means. Does it mean geometric shape or is area included in that? Say I have one sphere of radius r and keep fluid velocity, density, and viscosity constant and find its drag coefficient. Would...

Homework Statement 1. A pulley 150 mm diameter is driven directly by an electric motor at 250 revs min–1. A V-belt is used to transmit power from this pulley to a second pulley 400 mm diameter against a load of 200 Nm. The distance between the centre of the pulleys is 600 mm, the included...

Hi all, I encounter an un-explainable question during my lab, so I figured it would be a good shot asking here. Also, my English isn't perfect, so if there is anything unclear, say it out and I'm happy to clarify it. In the lab, we placed a sled on a track and slowly lifted one end of the track...

Hi all, Great forum. I really don't know if this is the proper place for this, so if it is not please forgive me. I have been researching reflective coefficients in transmission lines. I understand everything except steps 4 -> 5. Perhaps it is a lacking in my math skills but could someone show...

Hi all, I've been a long time reader of this forum but haven't signed up for whatever reason. So thanks for the wealth of information and solutions to my headaches. I'm trying to figure out a coefficient of temperature equation and I'm having a hard time with the manipulation for some reason...

Homework Statement Homework Equations Newton's 2nd Law The Attempt at a Solution I was wondering if anyone could verify that I have all the correct vectors or if I am missing any. I just wanted to check before I started trying to derive the equations. [/B]

Is it possible to predict the damping coefficient of a string using a mathematical simulation that included the string's diameter, length, frequency (and therefore tension), material density, and elastic modulus (if not also its Poisson's ratio) as opposed to simply looking at the amplitudes of...

Hey everyone! This is my first time posting here, so my apologies if I'm doing things wrong...which I probably am. So for my modern physics lab report, we're investigating the Hall effect. We measured Hall voltages as we adjusted a DC current source. The first question in my manual is to...

Homework Statement The top of a ladder of L and mass m is connected to a wall by a horizontal cable. The ladder makes an angle Θ=60 with the horizontal. A woman of mass 2m finds that as she climbs the ladder, the ladder begins to slip when she is one-third of the way up the ladder. Find the...

Homework Statement The polynomial of order ##(l-1)## denoted ## W_{l-1}(x) ## is defined by ## W_{l-1}(x) = \sum_{m=1}^{l} \frac{1}{m} P_{m-1}(x) P_{l-m}(x) ## where ## P_m(x) ## is the Legendre polynomial of first kind. In addition, one can also write ## W_{l-1}(x) = \sum_{n=0}^{l-1} a_n \cdot...

The problem is attached.

The fact that energy in a laser can propagate without much loss over long distances is quite shocking ! It's a renowned fact that energy is dissipated when propagation takes place through any medium... (I'm fully aware that laser is an exception) But I have quite a difficult time understanding...

What to do here if D=d/dx (D2+2D+4)y= x2e2x ? How to find particular integral by method of undetermined coefficient? if R.H.S would have been x2+ e2x then we could have taken yp= Ax2+ Bx+C + De2x but here in product, what to do?

Homework Statement A 4.30 kg block is pushed along a floor by a constant applied force that is horizontal and has a magnitude of 43.0 N. The figure gives the block's speed v versus time t as the block moves along an x axis on the floor. The scale of the figure's vertical axis is set by vs =...

Homework Statement A baseball is hit at a height of 3 ft off thte ground. It leaves the bat with an initial speed of 165ft/sec, at an angle of 10 degrees from the horizontal. The linear drag coefficient is k=0.38; gravitational acceleration is 32 ft/sec^2 Homework Equations [/B] Find a vector...

I'm trying to get my head around the calculation for coefficient of friction: COF = Friction/Normal force. And what happens if you vary normal force. Am I right in saying: The COF is a constant - every pair of materials has a specific COF which is independent of how hard they are pressed...

Homework Statement A crate on a rough horizontal floor is being moved horizontally by a force applied at a 16 degree angle above the horizontal. This is the smallest force that will move the crate at constant speed. What is the coefficient of kinetic friction? A : .11B : .27 C ...

Hi, I have been looking for formulae for the damping coefficient, and I found two different formulae for it. http://www.xyobalancer.com/xyo-balancer-blog/viscous-damping-coefficient This webpage states that damping force, Fd is given by Fd=-cv, where c is the damping coefficient while v is the...

I am working on a model for predicting cooling in a system that evacuates a vessel and cools by evaporation of water and the water vapor is condensed in a tube and shell heat exchanger. My concern is the prediction of the steam side heat transfer coefficient as the air is removed from the...

Hello, does anyone have a graph for the attenuation coefficient of Gold (Au) (y-axis) with the respective types of interactions with photons of various energies usually from~10^-3 to 10^4 MV (x-axis) and where the incoherent, photoelectric, compton etc...interactions occur? Doing work on this...

I want to calculate the flow rate from flow coefficient (cv ) ,so i need the testing methodology and procedure .please give an idea to clarify my doubts.

The mass of a steel block is 760.9 g, the static coefficient of friction is 0.15, how do i find the frictional force in Newtons?

Homework Statement Calculate {-3 \choose 0}, {-3 \choose 1}, {-3 \choose 2} Homework Equations In case of integer ##n## and ##k## { n \choose k}=\frac{n!}{k!(n-k)!}=\frac{n(n-1)(n-2)...(n-k+1)}{k!} The Attempt at a Solution I am not sure how to calculate this. Any idea?[/B]

Homework Statement A small smooth sphere of mass 3 kg moving on a smooth horizontal plane with speed 8 ms-1 collides directly with a sphere of mass 12 kg which is at rest. Given that the spheres move in opposite directions after the collision, obtain the inequality satisfied by e. Homework...

Hi everyone; How I can define the minor loss coefficient(pressure loss) of a filter which has 60nm pore diameter?

Homework Statement I had a question on my test that went something like: "A 20kg box is being pulled at an angle of 37 degrees across the floor with a force of 300N at a constant velocity. What is the coefficient of friction?" Homework Equations The equations I used to solve it were: Fpx= Fp...

I am looking for a reference to discuss the effects of resistor size on alpha, the temperature coefficient of resistivity. If we use the linear R=R0*(1+alpha*(T-T0)) alpha is a material constant, presumably for bulk-type resistors. Will alpha change as size (cross sectional area) of the resistor...