What is Wood: Definition and 228 Discussions

Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber.
Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the production of purified cellulose and its derivatives, such as cellophane and cellulose acetate.
As of 2005, the growing stock of forests worldwide was about 434 billion cubic meters, 47% of which was commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991 approximately 3.5 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction.

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  1. S

    Degree of freedom of a block of wood sliding on a horizontal plane

    Homework Statement Find out the degrees of freedom of a block of wood sliding on a horizontal plane. Homework Equations DoF=Nn-k N=no. of dimensions. n=no. of particles.k= no. of constraints. The Attempt at a Solution I am considering the block of wood as a rigid body made of n no. of...
  2. Austine-J5

    Making the body of a RC helicopter from balsa wood

    Holla peeps,in the nearest future I hope to make a rc helicopter. I've done a series of researches and so far things are falling into place but I've just hit a hard rock. All model Rc I've seen are either made of aluminum, plastic or panel boards so am wondering what about balsa wood? Its light...
  3. J

    Smells from Solid Matter: Wood

    If so, what about smells coming from solid matter, like wood?
  4. C

    Wood vs Metal (Interface Material)

    Hi all, I have an idea for a project whereby I there would be an electromagnet pulling on a metal weight through wood. So: Electromagnet -> Wood -> Metal The basic idea is to stick things to wood with electromagnets. Can anyone recommend a material that could be bonded to the Metal what...
  5. S

    Horizontal spring and wood block energy and equilibrium question

    Homework Statement A 200 g wood block is firmly attached to a horizontal spring. The block can slide along a table where the coefficient of friction is 0.40. A force of 10 N compresses the spring 18 cm. If the spring is released from this position, how far beyond its equilibrium position will...
  6. M

    PS4 horizontal on or elevated from wood

    I don't have a heat meter to test this so I just want to ask from a physics perspective what is more likely to be more effective. I noticed that my PS4 gets quite hot. I have it horizontal on a wooden surface. Ideally on top of a metal surface probably it would have been better since heat...
  7. Y

    Bullet Into Wood: Heat or Energy Loss?

    Hello, This is not really homework, but is in the context of my course. We always say that a bullet embeded into a wood does not conserve energy. We say heat is created. But, I was wondering: is the deformation of the wood considered heat released or is it some other kind of energy? Is...
  8. P

    Kinematics problem - Bullet in block of wood

    Homework Statement A 3.50kg block of wood is at rest on a 1.75-m high fencepost. When a 12.0g bullet is fired horizontally into the block, the block topples off the post and lands 1.25m away. What was the speed of the bullet immediately before the collision?The attempt at a solution d=1/2at^2...
  9. T

    Concerning vibration sustain, wire mounted to wood base and metal base

    tonequester here. Greetings to ALL. I have posted about acoustic resonance on my last couple of posts, and have been given much good info. I have one more post concerning concerning this topic.. I am going to do an experiment to find out the answer to my query, IF there is no definitive...
  10. N

    Oscilations: Bullet collides with wood block on spring

    Homework Statement A 6.20g bullet traveling at 485m/s embeds itself in a 1.73kg wooden block at rest on a frictionless surface. The block is attached to a spring with k = 79.0N/m A)Find the Period B)Find the Amplitude C)Find the totla energy of the bullet+block+spring system before the...
  11. V

    What is the spring constant of wood and how can it be determined?

    Homework Statement I'm modelling a plank of wood as a number of masses connected by springs. I need to know the spring constant of wood, but I am unable to find it and I'm not sure how to work it out?
  12. H

    Bullet hitting a wood block in a vise. Find initial velocity?

    Homework Statement A 7.00 g bullet, when fired from a gun into a 1.10 kg block of wood held in a vise, penetrates the block to a depth of 6.40 cm. This block of wood is next placed on a frictionless horizontal surface, and a second 7.00 g bullet is fired from the gun into the block. To what...
  13. R

    Inelastic Collision Bullet/Block of Wood

    Let me preface this by saying that this is a take home quiz and I'd really appreciate it if you didn't actually answer the question, I have outlined what I've done and what I plan to do to get an answer and I'm looking for input on my problem solving process. I have a problem that I've been...
  14. W

    Buoyancy of a piece of wood floating in water

    Homework Statement A piece of wood floats in water with 65% of its volume under water.Find the relative density of the wood. Homework Equations Buoyancy = (Weight of object) / (Relative density of object) The Attempt at a Solution B = W/s 1= .65/s s = .65/1...
  15. A

    How does oil affect the buoyant force of a block of wood versus water?

    Hi, I'm having trouble with a conceptual problem: Homework Statement There is a block of wood in a jar with water; it is floating. If I pour oil into the container, obviously the oil sits at a layer above the water. The wooden block touches the water, oil and air now. Did the volume of the...
  16. STEMucator

    Solving Friction & Wood Homework

    Homework Statement A block of wood which weighs 0.72 kg is being pushed across a floor. After 2s, the block has a velocity of 1.6m/s[F]. μK = 0.64. a) Find the net force acting on the block of wood. b) Find the force of friction acting of the block. c) Find the force actually pushing the...
  17. T

    What kind of wood should I use for a platform that holds 200 lbs

    I am making a flat platform with 4 leveling feet that can hold a heavy duty blower which is around 200 lbs. The platform is 21.5" x 22.5" as shown in this image (let me know if there are better designs): I thought about using 0.5" steel plate but with these dimensions, it will cost me $200+...
  18. P

    Calculating Strain in Wood Compression for Plotting Stress

    How can I calculated the wood strain in compression to plot it with stress, if the data that I have is the length and several extension data. The extension data corresponds since the 0 load to the the failure. Thanks. Since the equation for Strain is: ΔLength/Initial Length In order to...
  19. Monique

    What oil to use on nut wood furniture

    I have some walnut wood furniture (dining table, coffee table) that doesn't have a permanent finish. I've treated it in the past with boiled linseed oil that's dissolved in turpentine, but I'm looking for alternatives. I don't like the turpentine, would it be possible to use oil without the...
  20. medeek

    Designing a Wood Truss with Medeek Calculator App

    I recently started programming a basic web based app. that calculates the forces within a standard wood truss. I thought it might be of some interest to visitors to the Physics forums. I've added most of the common types of trusses used in residential construction, with more to come later...
  21. B

    Which wood cross section can carry highest uniform load

    Which wood cross sectioπ caπ carry hïghest uπiform load Homework Statement Homework Equations Moment of inertia for rectangle I=(1/12)bh3 τ=(VQ)/(I*b) σ=(MV)/I The Attempt at a Solution I started by finding reactions at B and C Then drew the sheer and moment diagrams (to save...
  22. M

    Newton's third law, bullet through wood question

    1. A 0.0048kg pullet traveling with a speed of 200m/s penetrates a large wooden fence post. If the average resisting force exerted on the bullet was 4500N how far did the bullet penetrate. 2. F=ma? 3. F = ma F/m = a 4500/0.0048 = 937500? So there's a reverse acceleration of...
  23. Q

    How do factories assemble hickory wood claw hammer?

    Hi guys, I am wondering about how people make wood claw hammer a simple one with just a handle, the head, and 1 wedge. It is fully automatic, let say they have all the parts previously made, and they only need to press a button to assemble all the hammer. How could the assembly be done...
  24. S

    F = ma 2012 #20 (Apparent weight when dunking wood in water)

    Homework Statement 20. A container of water is sitting on a scale. Originally, the scale reads M1 = 45 kg. A block of wood is suspended from a second scale; originally the scale read M2 = 12 kg. The density of wood is 0.60 g/cm^3; the density of the water is 1.00 g/cm3 . The block of wood...
  25. M

    Wood vs aluminium stiffness. What doesn't add up?

    AFAIK, the wood used for aircraft structures should have a specific stiffness, that is specific Young's modulus and bending strength, somewhat higher than aluminium (see attached image). If that is the case, why wood aircrafts are generally more subject to aeroelastic effects compared to...
  26. jim mcnamara

    Wood color stardards by species?

    http://www.fpl.fs.fed.us/documnts/fplrp/fplrp57.pdf Wood undergoes changes when exposed to direct sunlight (above reference) or incidental light. One of the changes is a change in color. Others include decreased film finish adhesion, and some other probably not so good changes. Walnut...
  27. U

    Fluid mechanics of floating wood

    Homework Statement A piece of wood is floating in water kept in a bottle. The bottle is connected to an air pump. Neglect the compressibility of water. When more air is pushed into the bottle from the pump, the piece of wood will float with a)larger part in the water b)lesser part in the...
  28. O

    Does Temperature Equalize Between Iron and Wood in Thermal Equilibrium?

    If I put an iron of 350K and a wood of 300K in contact, then put them in a container so that they are adiabatic. The question : after a very long time will they become thermal equilibrium? same temperature? My guess : they should be same. But they have different specific heat capacities. If the...
  29. R

    Wood-Burning Train: Is It Feasible?

    I understand a railway locomotive generates about 4 MW of power. Also understand that an area of about 130 acres of trees (high density) can generate 1 MW of power from a wood-biomass based power generator. As railways normally have a lot of land, can not the land adjoining the tracks be used...
  30. N

    Properties of Plank wood & bridge question

    Hello everybody, For a group project, we are supposed to propose several designes for a plank bridge over a river. I've tried to find this material's (plank wood) strength properties, or a stress-strain diagram to no avail. Do you know where I can find it? Also, is it reasonable for a...
  31. S

    Mechanic about wood block, friction and pulley

    Homework Statement Two objects A and B weighing 50 N and 80 N respectively were connected by a light string over a fixed pulley. A was put on a reasonably long and horizontal table surface. The coefficient of sliding friction between A and the table surface is μ = 0.3 while the friction...
  32. R

    Found a fossil. It's like wood - help identify?

    Found a fossil. It's like wood - help identify!? Hi, I found this fossil a few miles down the road in some pits. It has fossils on one side, and when cracked into it has all what I can presume is wood. It feels like wood, and is very smooth and can break off in flakes. You can see in the...
  33. X

    Physics bullet in wood; I can't figure it out?

    Homework Statement I can't figure this one out. I can't use any of Newtons laws to solve this, kinetic formulas, and w=Em+Ek doesn't seem to be working for energy. I know the answer, but I can't solve it. kg = kilogram m/s = meters per second m = meter A 0.002kg bullet is traveling at...
  34. 0

    Does Evolution has a role on beauty of Wood Duck bird?

    Does Evolution has a role on beauty of "Wood Duck" bird? Hey there, Lately I had a debate with a person on internet on whether beauty of Wood Duck has any relation to Evolution or not. At first he claimed that Evolution has nothing to do with beauty of species, and only narrow-minded...
  35. Z

    Art X-ray use on fine art wood panels

    Warm greetings from a first time poster, Thank you for looking. I hope I posted in the correct category and apologize if I did not. My question revolves around a late 19th century painting on wood panel made of cypress with oak strapping (2.6cm thick). I'm having the panel...
  36. L

    Radiocarbon dating of a piece of wood

    Hi Homework Statement A lance of wood is found wheres one piece contains 2,70 g 12^C. A scintillation counter shows 27,3 radiactive decay per minute. How old is the lance? Homework Equations N(t)= N_0 \cdot e^{-\lambda t} maybe half life of 14^C : 5730 years. The...
  37. M

    How Does Wood Slow Down a Bullet?

    Homework Statement A bullet of mass 0.0022 kg moving at 488 m/s embeds itself in a large fixed piece of wood and travels 0.56 m before coming to rest. Assume that the deceleration of the bullet is constant. What force is exerted by the wood on the bullet? F = N 1.01 NO HELP: Find...
  38. C

    Use a wood screw or a bolt & nut?

    I have what I think is probably a simple problem for someone with the right experience. I happened upon this forum while using Google. The drawing below (not to scale) shows the basic setup. There is wood mounting block. Adjacent to the mounting block is a 1/4" thick piece of wood with a...
  39. Spinnor

    Greased metal on wet wood rails, making pyramids.

    Of the materials available to the ancient Egyptians for moving large stone blocks, wooden sleds equipped with flat greased metal runners which might ride on parallel wet greased wooden rails gives a low coefficient of friction? It may not be easy to use such materials to make an efficient...
  40. Monique

    Find Quality Wood Veneer Furniture

    I'm looking for some new good-quality furniture for my new apartment that can last me many years. I already bought a large solid walnut-wooden diner table, first priority :biggrin: I came across a beautiful dresser that was walnut veneer. My impression was that wood veneer furniture would be...
  41. M

    A frog is riding on the top of a cylindrical piece of wood floating in

    A frog is riding on the top of a cylindrical piece of wood floating in still water. Half of the wood, with a diameter of 4 cm and length 20 cm, is immersed in water. The density of water is 1 gm/cc. What is the mass of the wood along with the frog? After the frog slowly goes into the...
  42. M

    Calculate Average Net Force of 20g Bullet Striking Wood

    A bullet of mass 20 g strickes a fixed block of wood at a speed of 320m/s. The embeds itself into the block of wood, penetrating to a depth of 6.0cm. Calculate the average net force acting on the bullet while it is being brought to rest.
  43. D

    Bullet passing through block of wood. Find max height of the wood.

    Homework Statement A bullet of mass 0.005kg is shot at a suspended block of wood with mass 1kg. The bullet initially has a speed of 200m/s, and passes through the block of wood. The bullet passes through the wood, and 50J of work is done deforming the shape of the bullet and block. If the...
  44. A

    Find the center of mass of a block of wood in oil

    A small square plank of oak floats in a beaker half full of water. The piece of oak is 7 cm on a side and 3 cm thick and floats on its side as shown in Figure P10.80. Density of oak 750kg/m^3 Density of water 1000kg/m^3 There were two parts to the problem, the first is: Find the location of the...
  45. U

    Displacement of wood block originally attached to spring

    Homework Statement A 180-g wood block is firmly attached to a light horizontal spring, Fig. 6-26. The block can slide along a table where the coefficient of friction is 0.30. A force of 20 N compresses the string 18 cm. If the spring is released from this position, how far beyond its...
  46. AakashPandita

    How wood is less dense than water?

    Wood is less dense than water. This means that particles of water are more close together than particles of wood. And so the kinetic energy of water particles should be less than the kinetic energy of wood particles. But it is not so. Why?
  47. K

    Bullet into block of wood on table edge

    Homework Statement A 17 g bullet traveling 475 m/s strikes a 0.7 block of wood that is balanced on a table edge 0.7 m above ground. If the bullet buries itself in the block, find hte distance D at which the block hits the floor. Diagram: Homework Equations Wnc = delta KE + delta PE...
  48. C

    Finding force(N) wood has against the bullet

    Homework Statement 22.0-caliber rifle bullet of mass 1.80 g, traveling at 320 m/s strikes a block of soft wood, which it penetrates to a depth of 0.140 m. The block of wood is clamped in place and doesn't move. Assume a constant retarding force. What force, in Newtons, does the wood exert on...
  49. J

    Energy conversion- burning wood to lifting an object

    Homework Statement If the calorific value of wood is 16 MJ/kg and a match weights approximately 0.17 g, then (a) how much energy (in joules) is released by burning the wooden part of a single match? If all of this energy were applied to do work to lift a 60 kg human vertically, against...
  50. K

    Building a wood bed platform - how much will it support?

    Because of size constraints in my room, I need a platform for my queen size bed that is the exact footprint of the bed (60" x 80"). I've decided to attempt to build it however I have no experience with this and hopefully someone can point out any flaws in my plans. I've attached an image...
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