What is Wall: Definition and 756 Discussions

A wall is a structure and a surface that defines an area; carries a load; provides security, shelter, or soundproofing; or, is decorative. There are many kinds of walls, including:

Walls in buildings that form a fundamental part of the superstructure or separate interior rooms, sometimes for fire safety
Glass walls (a wall in which the primary structure is made of glass; does not include openings within walls that have glass coverings: these are windows)
Border barriers between countries
Brick walls
Defensive walls in fortifications
Permanent, solid fences
Retaining walls, which hold back dirt, stone, water, or noise sound
Stone walls
Walls that protect from oceans (seawalls) or rivers (levees)

View More On Wikipedia.org
Recent contents Top users
  1. J

    2D momentum of two objects next to a wall

    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...
  2. O

    Beam suspended from a wall question

    N/A error in problem.
  3. L

    Finding a friction force (ladder leaning against a wall )

    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...
  4. P

    Vacuum vessel / distiller correct wall thickness?

    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...
  5. N

    Medical Coefficient of Friction Between Vaginal Wall and Penis

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

    How can I calculate post-collision rotation in my physics engine?

    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...
  7. I_am_learning

    Particle in a potential Well interacts with the wall without touching it?

    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...
  8. U

    Momentum Conservation: A Ball Strikes a Wall

    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...
  9. Z

    Why Does a Sliding Plank Lose Contact with the Wall at Two-Thirds Its Height?

    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 =...
  10. A

    Who has done research on the Planck wall

    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...
  11. P

    Force acting on a block against a wall

    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...
  12. G

    Find the Force Needed: Wood Box Sliding Down a Wall

    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...
  13. C

    Object against wall with horizontal force acting on wall

    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)...
  14. T

    Projectile Motion (Ball thrown against a Wall)

    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...
  15. M

    Conservation of momentum in Car Vs. Wall

    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...
  16. R

    Tennis ball rebounding off the wall question

    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...
  17. W

    What is the Work and Normal Force in a Block Pushed Up a Wall?

    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...
  18. P

    What is the Force Exerted by a Ball Against a Wall Supported by a Thin Wire?

    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...
  19. T

    Solving Physics Problems: Ball Thrown at Wall

    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...
  20. S

    Avg. Acceleration of ball against a wall with two velocities

    I searched the forum before posting and couldn't seem to find anything on the acceleration off a wall that wasnt dealing with force as well. Homework Statement A tennis ball with a velocity of +9.6 m/s to the right is thrown perpendicularly at a wall. After striking the wall, the ball...
  21. P

    Ball against a wall, statics.

    Homework Statement Here is a horrible diagram representing the problem: The problem is to find the minimum coefficient of static friction between the ball and the wall so that the ball remains motionless. Homework Equations torque = r*F The Attempt at a Solution I've divided the tension...
  22. H

    Find average force during contact when ball hits wall.

    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 44 m/s (about 99 miles per hour.) The ball moves toward the left, hits a wall and bounces straight back to the right with almost the same speed (44 m/s). As indicated in the diagram...
  23. H

    Uniform ladder on a frictionless wall?

    Homework Statement An 8.00m uniform ladder whose mass is 55 kg is resting against a frictionless wall. Its lower end is 750cm from the wall. If the coefficient of static friction between the floor and the lower end of the ladder is 0.60, calculate the reactions on both side of the ladder...
  24. N

    Can a Single Wall Support a Loft Bed and Its Occupants?

    Hello, as you can likely see I'm new here. I'll be blunt and state off the bat that I am not a physicist or engineer in any manner. Math has never been my strength which is why I spent my university life within the social sciences. I've always had an admiration for those within the natural...
  25. P

    Two cars driving 30 and 40 mi/hr is like hitting a brick wall at 70 mi/hr

    I hear this from people sometimes. Upon hearing about a bad head on collision, I will hear a person promptly add the two speeds together and claim the wreck for the drivers is as bad as slamming into a brick wall with that new speed (S = s1+s2). Is this really a good analogy? I'm not so sure it...
  26. T

    Weighing a Ladder While Leaning Against a Wall?

    Lets say you take a ladder and put it on a scale and measure it's weight while balancing it vertical. If you then lean the ladder at varying angles against a wall, would the scale's reading remain unchanged? I take it that it would, but for some reason this seems odd to me. Lets say the...
  27. S

    Calculating wind pressure against a rigid wall

    Consider a 10 m/sec wind blowing against a perfectly rigid wall. I want to calculate the pressure the wind produces on the wall. I'm ignoring the details of the actual physics of compression and turbulence. I'm reducing the problem to one cubic meter of (incompressible) air with a mass of 1.2 kg...
  28. S

    A Ball, A Wall and Momentum. (How is this incorrect?)

    Homework Statement This is a fairly straightforward question I'm sure. I have a ball. This ball has a mass of mass M. I throw this ball with a velocity v against a wall (perfectly along the x-axis (in the positive direction)). Now suppose the ball stays in contact with the wall for a time...
  29. A

    How Much Work Does the Wall Do to Stop a Skater?

    Wall excerts work on skater: Please help :( Homework Statement A 69.0-kg short-track ice skater is racing at a speed of 11.0 m/s when he falls and slides into a padded wall that brings him to rest. Assuming that he does not lose any speed during the fall or while sliding across the ice, how...
  30. L

    Calculate the tension in the tie-rope between the rod and the wall

    Homework Statement Hi again ,, My third Question of the day : A 250-kg block is supported by a cable attached to a rod of mass 100 kg that can pivot at the base. a) Calculate the tension in the tie-rope between the rod and the wall if it is holding the system in the position shown in...
  31. DrChinese

    Wall Street Journal on Entanglement

    Yes, entanglement has gone mainstream (if it wasn't already) with an article in the 5/6/2009 Wall Street Journal on the subject: Science, Spirituality, and Some Mismatched Socks : Researchers Turn Up Evidence of 'Spooky' Quantum Behavior and Put It to Work in Encryption and Philosophy The...
  32. Saladsamurai

    Fluid Mechanics~ Wall shear stress

    Homework Statement My main problem here is that I do not understand what they are asking. What is the wall shear stress? Do they mean the stress at the "floor" (or whatever you want to call it)? If so, I am assuming I use Newton's Law of Viscosity \tau=\mu\frac{du}{dy} since this is...
  33. S

    How can the falling block problem be solved using conservation equations?

    Homework Statement The problem consists of a block that starts off on a ledge. It has an initial vertical imperfection ie it is leaning over at the top such that when the top anchors are cut it will fall off of the ledge. I need to determine how far the block falls from the wall and the...
  34. S

    Longitudinal Waves (Heart Wall of unborn)

    Homework Statement A vet is using an ultrasonic motion detector to detect the heartbeat of an unborn chimp baby and claims that the speed of sound in the soft tissue of a chimp should be 1489 m/s. According to the manual which comes with the motion detector, the emitted frequency of sound...
  35. S

    Question on heat transfer of a plane wall

    Homework Statement A plane wall of 152 mm thickness has surface area of 2.32 m2. One side of the wall is kept at 82.2 oC, and the other side at 4.4 oC. The thermal conductivity of the wall material is 0.036 W/m.K at 0 oC, and that at 93.3 oC is 0.055 W/m.K. Calculate the rate of heat...
  36. S

    Sound isolation capacity of an idealized wall construction

    I'm looking to understand how to estimate the sound isolation capacity of a wall structure. With rising degree of detail will probably come an exponantial increase in complexity. I'm looking to start of, euhm,... gently. :shy: What I've gathered so far: -The impedance of the wall seems to take...
  37. A

    Wall of Death Problem: Finding Minimum and Maximum Speed for Rider Stability

    Homework Statement - FBD of description of forces - Mass of the rider ( is to decide ) = 70 kg - Dimensions of the Ride ( is to decide ) Height = 10 meters Radius = 10 meters Givens: gmax= 4 g Speed of bike = 80 Km/h Mass of Bike = 180 kg mu= vertical coefficient of friction = 1.00...
  38. DaveC426913

    Mounting big-screen TV on wall bracket

    I have a Samsung 42" similar to this one: http://www.hotchickshotpicks.com/wp-content/uploads/2007/09/samsung-42-inch-tv.jpg except that of course mine doesn't show sports. I've mounted it on a wall support but the TV does not seem stable. I can grab it and wobble it. The wall support is...
  39. A

    Impulse/Momentum ball into wall Problem

    Homework Statement 1) A 0.1 kg ball is rolling across the floor at 0.5 m/s when it hits a wall and reverses direction without any change in speed. A) Can you determine the impulse delivered to the ball by the wall? If so, what is it? If not, explain why not. B) Can you determine the...
  40. B

    So I plug in a circuit 299,792,458 meters long into my wall outlet

    Hope the subject caught your attention, I just wanted to clarify my some things about ac current... Ok, for our "circuit" we're going to have copper wire for simplicity's sake. Also, we're going to say that our Electric force travels at c on the wire. Just a big loop, no sharp turns, nothing...
  41. F

    Tension of string holding one mass to a wall, on top of another moving mass?

    Hello! This is my first post, I am taking an introductory physics course during my second semester of college and having some trouble with this problem. I hope I have followed the correct format, I appreciate any help that can be offered! Homework Statement A 4.82 kg block is placed on...
  42. X

    How many decibels does a regular apartment wall cancel out?

    How many decibels does a regular apartment wall cancel out?
  43. A

    What is the width of a wall seen from an opposing mirror?

    Homework Statement In a church choir loft, two parallel walls are 4.98 m apart. The singers stand against the north wall. The organist faces the south wall, sitting 0.967 m away from it. So that she can see the choir, a flat mirror 0.855 m wide is mounted in the south wall, straight in front...
  44. D

    Shadow Height on Wall: 2.6m Light Source

    1. A rectangular piece of cardboard 21.7cm high is held 1.0m in front of a point source of light. The cardboard is 2.6m away from a wall. How tall is the shadow on the wall? I have no idea how to do this my prof never talked about this in class and I looked threw the book with no help. I...
  45. P

    Magnet falling near an iron wall

    When a magnet is dropped from rest near an iron wall, it accelerates downward due to gravity at constant acceleration. It also accelerates toward the wall, and the closer it gets to the wall, the greater the acceleration. Can anyone refer me to a solution that would give the position of the...
  46. C

    Vander Wall Gas Thermometer: Ideal Gas Law and Triple Point Calibration

    Homework Statement A constant volume gas thermometer of volume V contains n amount of moles of gas. Assume the gas obeys the ideal gas law pv=nRt. The behavior is better described by: \left(p+a\frac{n^2}{V^2}\right)\left(\frac{V}{n}-b\right)=RT a=0.1, b=3e^-5. The thermometer is calibrated...
  47. S

    Average force exerted on object by wall

    [solved]Average force exerted on object by wall Handball A 301.0 g handball moving at a speed of 5.3 m/s strikes a wall at an angle of 29.0° to the normal of the wall and then bounces of with the same speed at the same angle. It is in contact with the wall for 0.002 s. What is the average...
  48. P

    A Structure Larger than the Sloan Great Wall?

    Does anyone believe, given new measurements from the SDSS, that we will discover a galactic wall that exceeds the size of the Sloan Great Wall? Also, what is larger than the galactic filaments connecting to form the walls? Can somebody please provide the proper topology of what the...
  49. P

    Calculate Force on Wall from Tornado Pressure: N Units

    Air within the funnel of a large tornado may have a pressure of only 0.46 atm. What is the approximate outward force F on a 6.2m x 5.5m wall if a tornado suddenly envelopes the house? Atmospheric pressure is 1.013 x 10^5 Pa. Answer in units of N. I know that P= F/A, so F=PA. I tryed just...
  50. B

    Gauss's Law: a nonconductive wall

    Homework Statement A nonconducting wall carries charge with a uniform denisty of 8.g µC/cm2. What is the electric field 7.00cm in front of the wall? Explain whether your result changes as the distance from the wall is varied. Homework Equations I'm still really new, I just...
Back
Top