Wall Definition and 735 Threads

http://ronney.usc.edu/AME101/AME101-F14-PS3.pdf number 1 in the link tyty

Homework Statement Consider a large plane wall with thickness L whose thermal conductivity varies in a specified temperature range as k(T) = k_{0}(1 + \beta T) where ##k_{0}## and ##\beta## are two specified constants. The wall surface at ##x=0## is maintained at a constant temperature of...

When you have energy going through a plane wall, I know that the heat flow rate should be constant, meaning what comes in should go out. But is this true even if it is transient, and a non-steady state process? I think the energy content of the plane will not change for steady state, but for...

Homework Statement A 5.00-kg block is held at rest against a vertical wall by a horizontal force of 100 N. (a) What is the frictional force exerted by the wall on the block? (b) What is the minimum horizontal force needed to prevent the block from falling if the static coefficient of friction...

I just bought a whiteboard for my wall, but I have a minor issue. While the top of it had brackets to secure it to the wall, the bottom of it has nothing to attach to the wall. Anyone have any suggestions on a good way to secure the bottom so it doesn't pop up when I'm writing on it?

Homework Statement I have this homework question and was able to set up the free body diagrams for the two blocks but got stuck forming the equations in part a. Please help if you can and give explanations - I want to understand the concept for my test coming up. A block with mass M is pushed...

Hi, I'm planning to build a climbing wall outside my house, attached to a concrete wall. The climbing wall would be 3 sheets of 18mm plywood (each about 30kgs) - each 2.5m x 1.22m (8ft x 4ft). With the boards set out 2.5m wide and stacked 3 high to give a max height of 3.66m (12ft). I want the...

I'm posting this because I disagree with the answer. Here's the question. You are in a train that is traveling at $3.0$ m/s along a straight horizontal railroad. Very close and parallel to the railroad there exists a wall with upwards inclination of $12^{\circ}$ with the horizontal. Looking...

Suppose that I am wearing some super boots that can allow me to travel anywhere from 0 to about 99% of c.Now I use these boots to travel alongside a wall and this wall at some point has a very sharp sword jutting out of it. It is safe to presume that anyone with the sword in his hand can easily...

Homework Statement Determine coordinate direction angle γ of the resultant force acting at B. Homework Equations Cos\gamma = F\underline{}z/F The Attempt at a Solution The first part was to find magnitude of F\underline{}b. The next part was finding the other coordinate...

Homework Statement There are two blocks against a wall on a frictionless table. I can't really manage a diagram, so please imagine this. There are two blocks, one of 5 kg and another of 10 kg, against each other. The 10 kg one is touching the wall. The frictional coefficient between the...

Homework Statement A particle is in the ground state of a L-box. At t = 0 the wall at x = L is suddenly moved to 2L. (a) If an energy measurement is made after the wall is moved, what is the probability of measuring the energy to be that of the ground state of the new box? (given solution...

I came across this problem in University Physics: (a) Oxygen 1O22 has a molar mass of 32.0 g>mol. What is the average translational kinetic energy of an oxygen molecule at a temperature of 300 K? (b) What is the average value of the square of its speed? (c) What is the root-mean-square speed...

Homework Statement In the figure, you throw a ball toward a wall at speed 34.0 m/s and at angle θ0 = 38.0˚ above the horizontal. The wall is distance d = 20.0 m from the release point of the ball. (a) How far above the release point does the ball hit the wall? What are the (b) horizontal and...

I though there's a simple ansatz for a particle in an infinite square well with a moving wall, i.e. in the interval [0,L(t)]. The eigenfunctions and eigenvalues for \left[-\frac{1}{2m}\frac{\partial^2}{\partial x^2} - E_n\right]\,u_n(x) = 0 are u_n(x) = \sin\left(\frac{2\pi n}{L}x\right)...

One of the problems in QM i frequently encounter in all textbooks is the shifting of the wall problem which goes like this. Assume a particle is in the ground state (or any stationary state) of an infinite potential well between 0<x<a. If the wall at a is suddenly shifted to 2a, then what is...

Homework Statement A man standing in the corner of the wall tries to climb up by pushing against both the walls, if the friction coefficient between the wall and his elbow is 'u' , then find the minimum force from which the man must push against in order to climb up the wall, given that he...

In an elastic collision against a wall, where the angle of incidence is equal to the angle of deflection, why is it assumed that friction effected no impulse, and only the normal force did? I can understand if this was stated in the problem by saying "frictionless surface, or whatever" but this...

I'm having a bit of difficulty conceptually understanding a problem. Hoping someone here can clear it up for me. In a simple circular condenser tube (which is cooled by water or air) what happens the tube wall temperature as the steam inside is condensed? Intuitively I would have thought that...

Homework Statement Hi guys, I have read this question over and over and have no idea where to start, would anyone be able to help. The Question Up to 20% of all heat lost in domestic dwellings occurs through walls. Many modern Australian homes are built by constructing walls...

Homework Statement Doing my homework I came across the question: why it would be better to have styrofoam on the inside of the house And why it could be better to have it on the outsideThe answer is The steady state will be the same for both but inside: warm and cold quickly Outside...

Afternoon all, I am interested to hear any and all suggestions as to how one would go about modelling the rise in temperature on the "safe" side of a wall, after a given time period over which the other side was exposed to a hydrocarbon pool fire. The configuration I have been looking at...

Homework Statement A woman throws a ball at a vertical wall d = 3.4 m away. The ball is h = 1.7 m above ground when it leaves the woman's hand with an initial velocity of 11 m/s at 45°. When the ball hits the wall, the horizontal component of its velocity is reversed; the vertical component...

Homework Statement Uniform rod AB with end B resting against rough vertical wall. Coefficient of friction between wall and rod is μ. Rod is 2m long and has mass 3kg. Rod is kept in limiting equilibrium by a light inextensible string, one end of which is attached to the end A of the rod and...

basic kinematics -- fox jumping over a wall problem Homework Statement A fox is 3.2 m from a 0.5 m tall wall. If it leaps from the ground towards the wall with an initial velocity of 12.0 m/s at angle of 18.9° above the horizontal, how high off the ground will the fox be when it reaches the...

How do I determine the force per square inch that a baseball would hit a wall? Assume the baseball was thrown at 50 mph? What would be the force? and does that translate into a weight or pressure? Obviously the ball would stop immediately. If we assumed it stopped like a baseball bat of...

Homework Statement Consider steady, incompressible, parallel, laminar flow of a film of oil falling down an infinite vertical wall (Figure P-1). The oil film thickness is “h” and gravity acts in the negative Z-direction (downward on the figure). There is no applied pressure driving the flow –...

forces -- A block slides upward on a rough, vertical wall Homework Statement A block slides upward on a rough, vertical wall at constant velocity when a force F of 60 N acts on it at an angle Ɵ = 60ᵒ to the horizontal. The mass of the block is 3.0 kg. See picture below. a) Using...

I am looking at an object that diffuses randomly inside a circular plane. What is the easiest way to find the expectation value for how long would it take on average to reach the wall if it was initially placed at a random position? If it is easier: what if the initial position were the...

Homework Statement A bullet weighing m = 50g with a initial speed of v = 300m/s hits a wall. The wall is build in a way that the value of the force it causes on the bullet is given by: . The time starts after the bullet hits the wall and F0 = 70N. How much does the bullet penetrate the wall...

Homework Statement In front of a long, straight, white wall a laser is hanged. Laser is parallel to the wall when we decide to rotate it with constant angular velocity for ##\pi ## so that the laser spot travels over the entire wall. The duration of the turn lasts just as long as it takes for...

Homework Statement A solid uniform 50kg ball of diameter 30cm is supported against a vertical frictionless wall using a thin 35cm wire of negligible mass (the wire is attached to the wall, the ball is attached to the wire and rests against the wall). Make a free body diagram for the ball and...

Consider the following potential function: V=αδ(x) for x=0 and V=∞ for x>a and x<-a , solve the shroedinger equation for the odd and even solutions. solving the shroedinger equation I get ψ(x)=Asin(kx) +Bcos(kx) for -a<x<0 and ψ(x)=Asin(kx) +Bcos(kx) for 0<x<a is it...

Homework Statement Homework Equations The Attempt at a Solution I have dealt with the case when the wall is frictionless and the rolling ball collide with it but I am not sure how to proceed here. When the ball comes in contact with the wall, the friction due to wall acts in the vertically...

Hello fellow scientists, I'm working on describing the heat that's being stored in a sanitation pipe when hot water starts flowing through the pipe. I'm starting off with a simplified approach by assuming that the water in the pipe suddenly changes from 20°C to 60°C. I found a good start by...

To preface my question, I know it is related to the Gibbs paradox, but I've read the wikipedia page on it and am still confused about how to resolve the question in the particular form I state below. Suppose a completely isolated ideal gas consisting of identical particles is confined to a...

1. The Question: A 10.0 g pith ball, carrying a charge of 1.52 μC hangs from a thread attached to a charged vertical wall carrying a surface charge density σ = 3.57 μC/m2. Find the angle that the thread makes with the vertical. Homework Equations [b]3. My attempt: Tcosθ=mg...

Quite late this afternoon I noticed a series of perfectly formed circles of light on the wall above my computer. Where are they coming from I wondered? Putting my hand in front and tracing one back the window, then climbing onto a chair it was clear they originated from the little holes at the...

Homework Statement A)A ladder of weight 80N rests against a smooth wall at an angle of 29 degrees to the vertical with its end on a rough horizontal floor.If the ladder is in equillibrium calculate the reaction (magnitude and direction) of the ground and the wall. Bi)a man of weight 80N...

Homework Statement A plank of length 2L leans against a wall.It starts to slip downward without friction.At what fraction of the initial height does the top of the plank lose contact with the wall . Homework Equations The Attempt at a Solution Let the normal force from the...

Homework Statement A ball of mass m= .25kg is moving with an initial velocity of \vec{v}=(8.0\hat{x}+8.0\hat{y})(m/s). It rebounds from a wall and has a final velocity (after impact) of \vec{v}= (-5.0\hat{x}+6.0\hat{y})(m/s) a.) Determine the impulse exerted on the ball by the wall...

20 m3 of gas at a pressure of 25 bar is to be stored in a cylindrical pressure vessel 2 m long. Given the following information : The yield strength of the vessel material is 14,000 psi If a factor of safety of 5 is to be used, determine: (a) Whether the vessel should be treated as a...

Homework Statement A stick is lying at rest against the wall. Which of the following statements is true? A) Friction must be present on both the wall and the floor surfaces. B) The wall surface must be rough, but the floor may be smooth. C) The floor surface must be rough, but the wall may be...

Hey guys and gals - I was constructing a circuit yesterday and a question developed in my mind. Power out of an outlet is about 120 VAC at like 20 amps as most all of you probably know. So if current MUST increase when voltage decreases how are there wall adapters that only put out 1 amp when it...

Hello! Hopefully this will be a fairly straightforward conceptual problem. A heads up - while this problem clearly deals with momentum and elastic collisions, we haven't actually covered these concepts in class yet. I'm getting the idea, but am still a bit hazy here and there. Homework...

Hi Guys, can I get some advice on how do I get started on the question? I'm guessing that natural convection is the key to solving the question. but i have no idea on how to solve it.

A 1.0 kg wood block is pressed against a vertical wood wall by a 12 N force (into the wall, at a 30 degrees angle up from the horizontal). if the block is initially at rest, will it move upward, move downward, or stay at rest? I'm working on the problem above, and through Google found this...

E is finite and V is infinite, So T should be negative infinite

Hi all, this is a problem with which I led myself in circles with for hours, because I kept forgetting to factor in a different thing each time. Long story short, I thought I'd cracked it, but my answer and the given answer are out by a square. Please see my efforts below! Homework Statement...

Velocity Calculation -- ball bouncing off a wall at an angle Question: "A ball is locked at 45 degrees towards a wall at 4 m/s. It bounces away from the wall at an angle of 45 degrees at 3 m/s. Find the change in velocity of the ball at the bounce." My attempt: So I know that change in...