Wall Definition and 735 Threads

I was wondering what the changes would be if the a) the lung compliance decreased and b) the chest wall compliance decreased. Am i correct in thinking both would result in a fall in FRC, or would that only be for a fall in lung compliance? In addition, what would happen to other lung volumes...

Exterior commercial frames (.053") embedded in a concrete wall 8" thick with 3" layers of polystryrene (3# density) on each side of concrete cavity. Frame rests on foam inside and outside of building. Frame is grouted solid with poured in place concrete. Is there an appreciable (to be...

Hi everyone, I have been on this forum since December last year. I have read many interesting threads by twofish-quants and many other members about the possibility of working in Wall Street after obtaining a Physics PhD. Although I understand that a career in Wall Street is really financial...

Homework Statement A 100-N uniform ladder, 8.0m long, rests against a smooth vertical. The coefficient of static friction between ladder and floor is 0.40. What minimum angle can the ladder make with the floor before it slips? The Attempt at a Solution Not really sure where to start...

What is the definition of shear stress in a cylindrical tube? It seems like sometimes that is written \tau = \mu \frac {\partial u} {\partial r} but then at some magic moment it gets rewritten as \tau = - \mu \frac {\partial u} {\partial r} so as to arrive at formula like \tau = -...

Please help: I need help to figure out the following: Given: An alluminum wall of thickness s. T outside wall, To T inside wall, Ti If the temperature changes on one side of the wall To, how long will it take until the the other side of the wall Ti reaches Tr, where To < Tr <Ti I...

Homework Statement A metal plate (with mass = 7kg and Length = 1.6m) is leaning against a frictionless wall and made an angle (Phi). The foot of the plate is made of circular edge that is situated at a V-grooved gap with angle (Theta). There are three normal force: F(wall) for the normal force...

A mass retaining wall having a vertical rear face is 0.4 m thick at the top and 0.8m thick at the base, is1.6m high and made of concrete of specific weight 24kN/m3. It holds back Earth with a specific weight of 18kN/m3 and an angle of internal friction of 20˚. The coefficient of friction...

Homework Statement Gas is contained in an enclosure in which one of the walls is a plane of area A. The wall acts as a frictionless piston, moving with constant velocity u in the positive x-direction, thus increasing the volume V of gas enclosed. A gas molecule of mass m approaches the...

Hello all, I came across what I think is a very interesting question the other day; How would you treat a particle trapped in a square well that had one finite wall and one infinite wall? Say for E[SUB]n[SUB]~(n*pi*(h-bar))2/(2m(L+2d)2) would you replace the 2d by 1d? As you can only find the...

Using a slingshot, the boy fires the 0.3 lb marble at the concrete wall, striking it at point B. If the coefficient of restitution between the marble and the wall is e= 0.6, determine the magnitude of the speed of the marble after it rebounds from the wall. initial velocity is 75 ft/s...

Homework Statement A uniform ladder 5.1 m long rests against a frictionless, vertical wall with its lower end 3.1 m from the wall. The ladder weighs 165 N. The coefficient of static friction between the foot of the ladder and the ground is 0.39 . A painter weighing 739 N climbs slowly up...

Homework Statement a uniform 2kg horizontal beam is 50cm long is bolted to a wall and supports a 5kg sign. calculate the tourqe produced by the combined weight of the beam and the sign about where it is mounted to the wall. Homework Equations tourqe = F x Perpendicular distance The...

I have computed the flow past a golfball and I am trying to calculate the shear stress on the surface of the golfball but I am having trouble figuring out how the wall shear stress is defined on 3D complex surfaces. When I am on the main part of the golfball that it is similar to that of the...

Homework Statement Suppose I throw a ball at a wall parallel to its x-axis. At the moment it hits the wall, what forces are acting upon the ball? Homework Equations None. Relevant assumptions: ignore any spin on ball. The Attempt at a Solution I think they'll be: -...

Homework Statement A bus is moving at 37.00m/s towards a wall. The sound from the bus has an original wavelength of 0.1500m. The sound from the bus reflects off the wall. What frequency sound does an observer on the moving bus hear from the reflection?? Homework Equations Moving Observer: fo...

I've seen this exact question in a book. (This is not homework) I've always thought this is because work has nothing to do with effort, but seeing this question on a book quite shocked me actually, is there any deeper explanation?

My friend and I have been discussing this for days only to discover we're completely ignorant of the forces involved: If I hit a golf ball at a brick wall that's, say, 5 feet away, will the golf ball take more damage from the wall, or from the club? Please, help me settle this lest I lose...

This Is really simple I just can't remember what way Sin and Cosine go Homework Statement Here is the problem: 7 (b) A uniform ladder rests on rough horizontal ground and leans against a smooth vertical wall. The length of the ladder is 5 m and its weight is 80 N. The angle between...

Basically I don't know where to even start. Does anyone know a good page that explains this topic? I would be very grateful if someone could provide a solution, but I know that's too much to ask. Thank you very much for your time.

Homework Statement The plane region defined by \[A = \left\{ {(x,y)/0 < x < 1,0 < y < \infty } \right\}\] defines the profile of a semi infinite wall, where there's a stationary regime heat flow. The left and right sides are isolated at 15º, and the base is isolated at 0º. Find T(x,y) in...

pls guide me in designing of linkeges of climbot

Assuming I have the same voltage, correct polarity, and sufficient current, can I generally replace any class 2 power supply with any other? This will be used for common household electronics. In particular, when researching power supplies, I see specifications for ripple, noise, setup, rise...

problem: ladder is leaning against the wall. There is friction between ladder and wall - f1 and there is friction between ladder and ground - f2 what is the minimal angle between ladder and ground that ladder doesn't fall down. I though it's easy, but then i realized it's not only about...

Would anyone only help me to compare the impact or damage of a Futsal ball against a wall versus a basketball ball. We have a new sport growing in popularity in the USA named Futsal. This sport is very popular worldwide and should soon become a Olympic Sport. In a few words, Futsal is soccer...

I am trying to calculate the force of a 2300 lb car hitting a wall at 40 mph. I know that momentum is mass x velocity and that force is mass x acceleration, but I'm not sure how they both relate to find the force on the brick wall. Any ideas?

Homework Statement A swimming pool has the dimensions 24 m multiplied by 9.0 m multiplied by 2.5 m. (a) When it is filled with water, what is the force (resulting from the water alone) on the bottom, on the short sides, and on the long sides? Homework Equations F = P*A P =...

A 10-ft chain weighs 24 lb and hangs from a ceiling. Find the work done in lifting the lower end of the chain to the ceiling so that it is level with the upper end. since you just take a little piece and add them up through an integral wouldnt it be the integral from 0 to 10 of 2.4x...

I am working on putting a new battery rack into a substation. I was re-reading the NESC and came across section 143. This section suggests it is not recommended to anchor my rack to both the floor and the wall. Can anyone explain why this is not recommended?

Hi physics folks- Every year for the past 3 years, I have built an ice rink in my back yard. Unfortunately, I do not have the flattest back yard, in fact it has quite a downward slope and then a steep uphill slope. But, I'm determined the make the biggest rink I can reasonably make, given...

Lets say a hot object is at 500K and placed in a chamber with wall temperature of 300K. The surrounding air in the chamber is 320K. So what is the mode of heat transfer for the hot objection? There is convection and radiation. so the heat transfer rate, q = q(conv) + q(rad), right...

Homework Statement We have two pucks next to a wall. Puck 1 has velocity v0=15 m/s in the direction y (as seen on the picture). Puck 2 is stationary. After the collision puck 1 moves in the opposite direction with velocity v1=10 m/s and puck 2 moves with unknown velocity in the direction x. The...

N/A error in problem.

1. Suppose that the actual coefficent of friction is one and a half times as large as the value of . That is, . Under these circumstances, what is the magnitude of the force of friction that the floor applies to the ladder? Express your answer in terms of , , , , , and . Remember to pay...

vacuum vessel / distiller correct wall thickness?? Hello! I have a vacuum vessel / distiller type of vessel with following:- Temperature inside the vessel max. 200°C [Celcius] and a Vacuum at max. -80kPa = -0.8bar Material: SS-304 = Stainless Steel Volume = 0.654m³ My main question...

Does anyone know the coefficient of friction between the vaginal wall and the penis?

I implemented collisions with walls in my Java physics engine, complete with elasticity and friction, but I am not sure how to calculate the post-collision rotation. Maybe you can help? Here is the wall collision method (if you can understand it) : public void processWallCollision(Vector...

Particle in a potential Well interacts with the wall without touching it? The ground state Energy for a particle in an infinite potential well is given by E = h2 / 8mL2 Consider a particle with high mass, say 1 kg. Then the ground state Energy will be very very low. So the velocity of the...

Homework Statement A ball whose momentum is p strikes a wall and bounces off, The change in the balls momentum is: A- 0 B- P C- 2p D- p/2 E-Infinity Homework Equations The Attempt at a Solution It's simple question but I want to make sure if my answer is true. The change in...

Homework Statement A Planck of length L2 leans against a wall. It starts to slip downwards without friction. Show that the top of the plank loses contact with the wall at 2/3 of it's original height. Homework Equations F*R = torque Moment of Inertia of Rod (I) = 1/3 M4L^{2} Mgh =...

I am interested if you know somebody who did research, a theory beyond the Planck length, equal to 1.616252(81)×10−35 meters; between 0 meters and Planck length. Are some Big Bang theories...

Homework Statement A 1.0 kg wood block is pressed (30 degrees) against a vertical wood wall by a 12N force as in the picture. If the block is initially at rest, will it move upward, downward, or stay at rest? In the book, it gives the us as 0.50 and the uk as 0.20. Free Body Diagram...

Homework Statement A m = 2.7 kg wood box slides down a vertical wood wall while you push on it at a θ = 35° angle. What magnitude of force should you apply to cause the box to slide down at a constant speed? Homework Equations The Attempt at a Solution I got 64.5766 N for the...

Homework Statement A horizontal force F of 16 N pushes a block weighing 6.0 N against a vertical wall (Fig. 5-47). The coefficient of static friction between the wall and the block is 0.61 and the coefficient of kinetic friction is 0.41. Assume that the block is not moving initially. (b)...

Homework Statement You throw a ball toward a wall at speed 24.0 m/s and at angle θ0 = 37.0° 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 (c) vertical...

If a car crashes into a solid unbreakable wall, how is momentum conserved (I know it must be). To me, it seems that the car will just "stop" and the wall will not move. If momentum is to be conserved, the car should either move through the wall, (which doesn't happen) or the wall should move...

Homework Statement A tennis ball has a mass of 0.057 kg. A professional tennis player hits the ball hard enough to give it a speed of 50 m/s (about 112 miles per hour.) The ball moves toward the left, hits a wall and bounces straight back to the right with almost the same speed (50 m/s). As...

Homework Statement A 2.0 kg block is pushed 3.0 m at a constant velocity up a vertical wall by a constant force applied at an angle of 27 degrees with the horizontal. The acceleration of gravity is 9.81 m / s2. If the coefficient of kinetic friction between the block and the wall is...

Hi, I am having trouble figuring out how to start this problem, I have a free body diagram, but I am not sure which equation to use to help me solve for this, please help! A solid form 42 kg ball of diameter 32 cm is supported against a vertical frictionless wall using a thin 30cm wire of...

Homework Statement You throw a ball toward a wall at speed 24.0 m/s and at angle θ0 = 41.0° above the horizontal (Fig. 4-35). The wall is distance d = 21.0 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...