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.
There is an experiment to determine the Young's Modulus of the wood which involves bending it.
The equation used to calculate it is like this
E=WX3/4ZDY3
Where D=amount of bending
W=force (N) which causes the bending
Z=width of the wood
Y=thickness of the wood
X=horizontal distance between the...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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?
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...
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...
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...
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...
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...
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+...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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.
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...
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...
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...
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?
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...
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...
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...