Wood Definition and 229 Threads

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. Phil App

    Enthusiast in the field of technology and science

    I am a 20-year-old man who has graduated in the field of wood technology and its industrial applications. However, I am very interested in many aspects of science and technology, even though I do not have the necessary education and experience. I enjoy contemplating things theoretically, even at...
  2. DennisN

    News Archaeologists discover world’s oldest wooden structure

    Archaeologists discover world’s oldest wooden structure (University of Liverpool) Article: https://news.liverpool.ac.uk/2023/09/20/archaeologists-discover-worlds-oldest-wooden-structure/
  3. abdulbadii

    Reading a wood cutting blade specification

    How do we read and understand a wood cutting blade specification (e.g. below) ? Is the grinder spacer flange nut for 16 mm center diameter metal cutting disc can safely be used for 20 mm one of such blade?
  4. P

    Static Friction Question — A wood block sliding on a tabletop

    I have no idea how to start this other than that I think that Fn is 17.64N and Fnet is 0. But I don't have the mew, so I am not sure how I am going to get the force of static friction.
  5. Strato Incendus

    Wood as a precious resource on spaceships

    A lot of fictional examples of interstellar spaceships, be they generation ships or sleeper ships, have some sort of arboretum. However, those often just tend to be places for recreation, like a forest for joggers. Or, if the ship is transporting any animals, too, those might inhabit the...
  6. A

    Wood as a carbon neutral biofuel

    Moderator’s note: discussion spun off from https://www.physicsforums.com/threads/the-nuclear-power-thread.9091/page-43#post-6558385 Sometimes I don't understand the Germans, so technically advanced and forward thinking and yet somehow willing to abandon logic on this one. Their alternative is...
  7. qnach

    Automotive How Can You Measure Wood Plate Thickness from One Side?

    I have access to only one side of the plate, i.e. cannot clamp both sides of the plate to measure. Is there any way, perhaps acoustic methods, to measure a plate thickness from only one side?
  8. J

    Anyone here interested in wood gasification.... can't find anything?

    Wood gasification is the process of converting solid wood into a gaseous fuel. Surely the brainiacs on this site would find it interesting.
  9. duchuy

    Ballistics -- How deep does the bullet penetrate into the wood?

    Hi, I was given this exercice where I have to calculate the penetration distance, knowing that m = 20g, v = 300km/h and C = 750 N and I have to give the results with two significant numbers. I really thought that all I had to do was replace the values so I did : d = (20.10^-3) x (300/3,6)^2 /...
  10. S

    Wood/Glass/Metal Why are two-part wood bleaches mixed before being applied?

    Wood Magazine https://www.woodmagazine.com/materials-guide/finishes/get-the-color-out-with-wood-bleach descibes the chemistry of two-part wood bleaches as follows: Since they neutralize each other, why are the two parts mixed before being applied to wood?
  11. person123

    Why are two pieces of wood stronger when bound together?

    The answer learned in class is that the two 2*4s are able to distribute the load over both of them, but I don't think this is an actual answer because that's balanced by the fact that each block is half the area. Does anyone know of the reason for this observation? Thanks!
  12. S

    Are there advantages to wood pellets over wood chips?

    Both wood chips and wood pellets can be automatically feed into the burn chamber by Screw Conveyors, transport belts, and vibratory feeders. And both make char that is small enough to be automatically removed from the burn chamber. And both also has a shape and size that allows enough air to...
  13. Petext

    Momentum Problem -- Bullet fired into a block of wood

    A gun is fired vertically into a block of wood(unknown mass) at rest directly above it. If the bullet has a mass of 24.0g and a speed of 310 m/s, how high will the block rise into the air after the bullet becomes embedded in it?
  14. G

    Wood Ash vs Charcoal Fertilizer: Comparing Nutrients

    I took 2 chemistry classes in college but that was 50 years ago, I have forgotten more than I ever knew. I watched several educational chemistry classes on YouTube then realized it will be a very long time before I can answer this question on my own. Questions is. Wood ash is an excellent...
  15. phinds

    Insights Tell One Wood from Another: Basic Wood Anatomy

    Continue reading...
  16. T

    Help with a problem about motion — bullet striking a block of wood

    I first plugged my given values into m1v1+m2v2=(m1+m2)vf. (0.002)(600)+(5)(0)=((0.0020)+(5))vf vf=0.24 m/s Next, I plugged my given values into F=ma. ((0.002)+(5))(9.8) F=49.02 N Next, I plugged my given values into Fdeltat=mdeltav. deltat=mdeltav/F ((0.002)+(5))(0.24)/(49.02)...
  17. K

    B Resistive force that a nail will have to overcome to penetrate a piece of wood

    lets say a hammer of 0.5kg strikes a nail at 10m/s. The nail penetrates into the wood by 1cm. The reason why the nail stops is because friction has eventually overcome the nails momentum. The retardation of the nail can be worked out, but Can you calculate the force that stops the nail if you...
  18. S

    Store wood in old salt mines to reduce CO2 in the atmosphere

    If trees are cut and then burned they have not reduced the CO2 in the atmosphere at all. And if they are left in the forest and then rot 90% of their mass also go back into the atmosphere. Here in Germany we have many old salt mines. I wonder if it would be a good idea to cut trees and store...
  19. V

    What happens to frozen wood frog's brain?

    Summary: A wood frog can freeze and then live again. What happens with the frog's brain, memories, etc? It is known that wood frog can freeze and subsequently resurrect and live on. Are any ideas about the personality after defrosting of frog? I mean this frog is technically dead more than a...
  20. naji0044

    Inelastic collision problem: Bullet striking a wood block

    Hey everyone I'm struggling on the last part of this assignment. I need to find the total work done by the block and the bullet, when the collision happens. The informations is: mblock=0.3 kg mbullet=0.01 kg vg=700 m/s Height=0.72m The final speed after the collision is vf=22.6 m/s and the...
  21. CynicusRex

    Appropriate tightness of bolts between skateboard and trucks

    As you can see in the pictures below the trucks are attached to the skateboard with four screws nuts and bolts, with a 2~3mm piece of rubber between the truck and the board. I've always wondered if tightening the screws bolts harder, decreases or increases the strength of the 7-layered plywood...
  22. B

    Steel chisels cutting wood and bone

    Below 17 degrees bevel , a steel chisel cuts pine wood without tearing shreds but 25 degrees is the upper limit for hardwood. Bone is said to resemble wet pine-wood. 2mm thickness is the limit for steel cutting bone. .". difficulties arise for the surgeon when using conventional chisels, due...
  23. C

    Work Problem -- Wood Block Sliding into a Spring

    W_net = Integral from 0 to 0.70 meters [ - F_spring - F_friction ] = 1/2 * (-k) * x^2 - mu * mg * normal force * x = 1/2 * (-325N/m) * (.70)^2 - 0.250 * 6kg * 9.81m/s^2 * 0.70 - 0 = - 89.93 Joules Is this correct and am I setting this whole thing up correctly? The negative signs have me...
  24. A

    Misc. What is the Net Energy Yield for Wood Syngas?

    Hello, My name is Adam and I am experimenting with wood gas. I recently came across a really cheap wood chip source and would like to compare it against electrical utility prices. I am curious if running an old generator would be cheaper than off peak rates of $0.065/kwh. As of right now, I...
  25. M

    B Spiral piece of wood moves upstream

    Hi I have found a video which is composed of 2 videos. In the first one you can see that a spiral branch is put into a stream and starts to move by itself in a snake like motion. In the second video similar spiral piece of wood is floating in a container and then water is poured into it and it...
  26. Q

    How light rays from a fireplace wood fire on Earth compare to the Sun's fire?

    While lying in front of a 500 degree woodfire, I wonder if besides light and heat that we take as ordinary does it also have ultraviolet rays of light like the sun?? What are the types from light from an ordinary on Earth fire?? Would they be beneficial to plants as main light source?, would...
  27. D

    MHB How Can I Efficiently Cut Wood Boards of Different Lengths?

    Hi, New to this forum so sorry if i am not posting in the right place. I have a problem, I need to cut a number of pieces of wood to certain lengths (the width and depth are standard and not relevant here). I know the number and lengths of all the lengths I need, but i can only buy the wood...
  28. O

    Energy Conservation: Puck on Wood on Frictionless Surface

    Homework Statement Hey all, another problem. There is a 1 meter wooden panel that is on a frictionless surface. A puck is placed on one end of the panel and is pushed towards the other side. The mass of the panel is 10 times that of the puck. Also, there is a friction coefficient of uk=0.15...
  29. kyphysics

    Why don't wood construction sites get damaged in the rain?

    They're building new condos across from my parents house right now (adjacent neighborhood). I see this site everyday and it's growing. Right now, they've got a lot of the framework up for the condos and it's all wood (as far as I can tell). It's also raining a lot here. Question - why...
  30. N

    News Illegal wood pellet business in Chernobyl Zone

    Investigative journalists discovered that the wife of deputy head of National Police of Ukraine (his name is Igor Kupranets) is a "successful businesswoman", but this is hardly unusual in our country. What is a little peculiar is that her business is in making wood pellets, and it is located in...
  31. S

    Changing my wood chipper's engine

    Hello everyone I have a wood chipper as shown in photos attached to this message called 'Morbark1.jpg' and 'Morbark5.jpg'. The engine on it as standard (Kohler Command CH25s 25hp) is too much hassle, time and money to fix and repair. My question is I wish to attach another engine onto the...
  32. Greg Bernhardt

    Chemical/Paint Paint bubbling off wood beam DIY help

    As you can see from the image a vertical portion of my wall (a wood beam) has developed this vertical bubbling where the paint is being rejected. It spans from the ceiling to floor. First thing I thought of was water damage, but as I chip away at the paint and get to the wood it doesn't seem...
  33. Nitesh Swarnakar

    B Why does ice piece sticks on hand but not wood piece?

    Why does ice piece sticks on hand but not wood piece?
  34. I

    Concentrating diesel fuel and or wood into liquid fuel?

    I was looking at btu numbers for common fuels and noticed 1 barrel of crude oil (42 gallons) contains 5,800,000 btu's with diesel fuel containing 139,000 btu's per gallon would it be possible to concentrate 42 gallons of diesel fuel to get more btu's per gallon? Also the wood into liquid fuel...
  35. E

    A bullet pushing a knot out of a wood block

    Homework Statement You shoot a 0.0050-kg bullet into a 2.0-kg wooden block at rest on a horizontal surface (Figure 1) . After hitting dead center on a hard knot that runs through the block horizontally, the bullet pushes out the knot. It takes the bullet 1.0 ms to travel through the block, and...
  36. hackhard

    Can Wood Be Used as a Capacitive Sensor in an LM358 Op-Amp Circuit?

    i connected pin 4 and 8 to gnd and +5 v respectively .when pin 2 touches wood, or hand pin 1 is high. i understand skin is capacitive , but wood?
  37. W

    Do not try this at home kids......

    Found this interesting video - thought there would be interest here... VIDEO LINK
  38. L

    B Hammer & a nail -- Calculating penetration depth into wood for first strike

    If you know the weight of the hammer, and the velocity it hits the nail. What would you need to know about friction forces, etc in order to calculate how far it is driven down into the wood? So assume the hammer weight 0,5kg and it is being swung at 50m/s when it hits the nail. Friction is (?)...
  39. SadPanda6022

    Density floating problem, wood and lead

    1. Homework Statement A block of wood has a mass of 3.47 kg and a density of 628 kg/m3. It is to be loaded with lead (1.13 × 104 kg/m3) so that it will float in water with 0.848 of its volume submerged. What mass of lead is needed if the lead is attached to (a) the top of the wood and (b) the...
  40. V

    Steam's Effect on Wood: A Gedanken Experiment

    I have a piece of wood, I decide to insert it into a steamer to observe what happens, because I'm not sure. There could be multiple possibilities. Wood has conductive tissue, steam may get trapped within pressing it outwards. The temperature dependent expansion definitely happens. But steam not...
  41. K

    A wood block is launched up a ramp

    Homework Statement A 3 kg wood block is launched up an inclined wooden ramp that has an angle of 25° to the horizontal. the Block's initial speed is 12 m/s and the kinetic coefficient of friction is 0.2. What is the vertical height the block reaches above it's starting point? What speed does it...
  42. Shadow-Shocker

    Can PEG waterproof wood without altering its appearance?

    Hello I found a recipe for making a type of waterproof wax using beeswax and paraffin wax, and I plan to coat this type of wax with a piece of wood. Does anyone know with this type of wax, after coating the piece of wood, will the wax still prevent the wood from expanding in water?
  43. Hexogen

    Wood Shield For Magnetic Field?

    So, I was watching PBS's Nazi Mega Weapons, and they were discussing the V-1 terror drone when they said something that made me scratch my head. They said that the Nazis initially had problems with the compass that facilitated navigation because of magnetic interference from the metal in the V-1...
  44. R

    How much energy transferred when we burn a piece of wood ?

    Hi All, If we burn a piece of wood having mass 1 Kg, in a closed surrounding (Box), If box is 1 cubic meter in size and box is perfectly heat insulated . Will all energy of wood , say 3,890 K cal/Kg , get transferred to air surrounding it ? How much temperature rise of the air will occur...
  45. Fatima Silva

    Medical A material light, cheap and strong as wood material

    Good evening. I'de like to know if exists a material light, cheap and strong as wood material, capable of handle maximum 100 pounds. . that's for a portable massage table structure.
  46. A

    Supporting a plank of wood with a mass at the centre

    Homework Statement "Two people are holding a plank of wood at either end, with a mass located at the halfway point between them, they both walk backwards extending their arms, the mass still being halfway between them. The plank becomes harder to support, why is this?" Homework Equations Maybe...
  47. S

    Would you -- drawing of wood blocks and a ruler to measure a lens

    < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown. Also, thread title edited to make it more descriptive. > The question is asking me to draw a diagram to show how, in the laboratory you would use two rectangular blocks of wood and a metre rule...
  48. B0b-A

    Could a Stone Age Axe with a Wooden Handle Redefine Ancient Human Technology?

    Stone age axe found with wood handle ... http://www.bbc.com/news/science-environment-30197084
  49. P

    Help- Thin cheap board/plastic for waterproof poster

    Hi all- I am trying to make a semi-waterproof poster (only needs to be wet for a few hours and not necessary for the poster to last beyond the day) I need to back the poster on a hard surface - have tried correx but it won't accept any titebond glue as it is basically treated to be resistant...
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