Wood Definition and 226 Threads

Homework Statement A 10g bullet strikes and becomes embedded in a 0.200kg block of wood placed on a horizontal surface just in front of the gun. If the coefficient of sliding friction between the block and the surface is 0.4 and the impact drives the block a distance of 8m before it comes to...

Hello Is there some data or some formulas to calculate how much does steel wire creep at a constant stress? If I have, for example, a 1 m steel string with 1 mm diameter under a constant tension of 1000N at a temperature of 20C, how much does it creep or lengthen in a year? I tried...

hey guys, I came to your great forum because of a tv episode on nat geo the other night. Evo posted a thread that is creating a lot of waves in the prepping community https://www.physicsforums.com/showthread.php?goto=newpost&t=510194" but anywho I digress, I asked a question about building...

Hi, :smile: I am learning about thermal physics and I have a doubt: Say that water and a box of wood, both with the same mass, are at 50 degrees Celsius. This does not mean that they have the same amount of energy (internal energy in this case?) right? That is because in water for...

1. A 2.3kg wood block hangs from the bottom of a 1.0kg, 1.2m long rod. The block and rod form a pendulum that swings on a frictionless pivot at the top end of the rod. A 10g bullet is fired into the block, where it sticks, causing the pendulum to swing out to a 33degree angle.Homework Equations...

Homework Statement I have this Physics coursework, where I have been investigating how the resonant frequency of wood changes as I increase the length of the wood and the width, by using increasingly long and increasingly wide panels of thin MDF. What I would expect to see would be a decrease...

Homework Statement A solid wood door 1.00 m wide and 2.00 m high is hinged along one side and has a total mass of 41.0 kg. Initially open and at rest, the door is struck at its center by a handful of sticky mud with mass 0.700 kg, traveling perpendicular to the door at 11.0 m/s just before...

　 Is the Energy Band of Wood vs Crystals similar? 　 As I understand it. In crystals the interaction of the atoms are more intimate.. meaning all the atoms in the crystals can influence one another which produced solid energy band. While in wood, the distance are further and hence the...

I think my friend is messing with me. He says it is common knowledge that diamonds do not cut wood. I know that if I had the money and I made an ax with a diamond head and made it razor sharp and made an ax from carbon steel with an equally sharp blade, the diamond one would cut better and never...

In my engineering class, we were told to create a structure out of balsa wood (1/8"x1/8") and glue. The structure has to suport the weight of 3 15lbs. weights (donut shape). We are only give 72" of balsa wood, and the structure must hold the 3 15lbs. weights for 1min. Sorry I am new to this...

Homework Statement A 50g bullet traveling horizontally at 200 m/s embeds itself in a much more massive wooden block initially at rest on a horizontal surface ( \muk = 0.10). The block then slides 1.2 m toward an ideal spring and collides with it. The block compresses the spring (k=600.0 N/m) a...

A block of wood with a density that is 750 kg/m3 is floating in a tank of water. How much of the wood is above the surface of the water D=M/V I've been trying for hours to try to figure this one out. The only info I'm given the the density of a block of wood in the water at...

Homework Statement For the following problem: A piece of balsa wood with density .50 g/cm^3 is released under water. What is its initial acceleration? I have gotten this far: Fnet=Fbuoy-mg -ma=p(water)gV(displaced)- p(wood)g(Vdisplaced) =(p(water)-p(wood))gV=-ma where p="rho" But in this...

Homework Statement A 50g bullet traveling horizontally at 200 m/s embeds itself in a wooden block, initially at rest, on a horizontal surface (μk=0.1). The block slides 1.2m toward a spring and collides with it. The block compresses the spring (k=600 N/m) by 20 cm. Find the mass of the wood...

Homework Statement the coefficient of starting friction for wood on wood is 0.55. What is the force of friction of a wood block of mass 3.5 kg being pulled on a wood floor? Homework Equations i think i use the formula F=mMA where F is the force needed to move a solid from rest...

Suppose a uniform cube of wood floats on the surface of water. Water wets it completely. Will it be buoyed up or down by surface tension? The force of surface tension is tangential to the liquid surface (along the surface of liquid). So I think there is no effect on buoyancy of cube due to...

1. a mass m1=5g moving to the right at a speed of 100m/s undergoes a perfectly inelastic collision with a block of wood, m2= 100g, at rest. what is the speed just after the collision? 2. if the mass and block of wood described in question #1 are parts of a ballistic pendulum of length 2m...

Can we built the [SIZE="4"]small passenger car [SIZE="3"]body using [SIZE="4"]ANY WOOD which is [SIZE="7"][SIZE="5"][SIZE="4"]STRONGER and [SIZE="5"][SIZE="4"]CHEAPER? If so, name the wood.

Homework Statement A rifle with a barrel length of 56 cm fires a 10 g bullet with a horizontal speed of 350 m/s. The bullet strikes a block of wood locked in position and penetrates to a depth of 13 cm. What resistive force (assumed to be constant) does the wood exert on the bullet...

Homework Statement See attachment! Homework Equations Fk=UkN The Attempt at a Solution I can't find a way to start this problem can someone guide me please!

Homework Statement A bullet leaves the muzzle of a rifle at an unknown velocity and strikes a wooden block that is suspended by a piece of string. If the block swings backwards to make an angle of 40 degrees, at what velocity must have the bullet been traveling when it struck the block? mass of...

I am designing a wood splitter capable of splitting a 42" diameter log into 42 pieces in one cycle. The design utilizes a stationary multi-wedge splitter that will cut the log like a french fry press. The strongest hydraulic cylinders used in industrial firewood applications is about 90 tons...

Homework Statement An 19-g bullet is shot vertically into an 5-kg block. The block lifts upward 5 mm. The bullet penetrates the block in a time interval of 0.001 s. Assume the force on the bullet is constant during penetration. The impulse on the block due to capture of the bullet is closest...

The Section modulus of a beam that I compute does not match wood design tables to determine the correct size of the wood framing member. Can anyone offer some insight? I have to size a wooden beam. The span is 24 feet with a tributary area of 10.5 feet. The dead load value is 85psf, the...

I was in the shop the other day cutting holes out of a 20inx20inx.25in piece of plywood and I noticed that the hole saw was slipping on the board (meaning that it would begin to make an unpleasant sound as the saw hit the board). I had the board clamped down and I realized that a large portion...

anyone know a value for the coefficient of friction of wood on rubber? rhys

In normal conditions, it takes a long time for wood to burn. But if you add some oil (or something similar like butter) it tends to burn faster. So, does adding such additives increase the calorific value? What makes the wood burn faster? Is the "faster" burning of wood and calorific value...

So, I was just chopping the wood, and the way I do it is this : I get the axe wedged in the wood (duh), but instead of going all the way through like that, I get out a hammer and use it on the axe (which applies a downward force), and thus the wood is split. (I may draw a picture if this is hard...

Hi everyone, Please refer to the attached diagram. I was playing around with pulling tablecloths out from the bottom of plates and objects resting on it, and was getting good results. I also happened to have a cuboid wooden paperweight which was on the table cloth and I noticed that that...

I need to make a bridge using Balsa Wood, but I can't decide whether to use the Howe or Pratt Truss. Requirements maximum mass of 25 grams maximum test load will be 15kg must allow a 5.0 (∼2”) cm cube to pass along the roadway without touching the structure must be an opening at the...

Homework Statement A block of wood with volume V floats in water with 0.68V submerged. In oil the block floats with 0.86V of its volume submerged. Find the density of the wood. Homework Equations \rho = M/V The Attempt at a Solution I'm not really sure about how to...

Homework Statement A wooden block with a length of 10 cm and a mass of 1 kg lies on an icy plane. A projectile with mass of 2 g hits the wooden block with velocity of 300 m/s and breaks through its center of gravity. How much are the final velocities of the wooden block and the projectile...

I and few of my pals are making a project. A circular blade woodcutter saw powered by bicycle pedalling for cost effective design for rural people where electricity is a problem... We plan to cut Logs with it...and their cross section can be random... Using a big circular blade. Now...

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 Consider a bullet of mass m fired at a speed of V0 into a wooden block of mass M. The bullet instantaneously comes to rest in the block. The block with the embedded bullet slides along a horizontal surface with a coefficient of kinetic energy \mu. How far does the block...

Homework Statement I'm working a homework problem that states: A very old specimen of wood contained 1012 atoms of 14C in 1986. • How many 14C atoms did it contain in the year 9474 B.C.? • How many 14C atoms did it contain in 1986 B.C.? Homework Equations N(t) =...

Hi, I am currently constructing a science fair project, and I was wondering if anybody knew any thin material that was relatively light weight, cheap, and as strong as wood. I understand that carbon fiber exists, but this material is rather expensive. If anyone knows alternatives to using wood...

http://news.yahoo.com/s/ap/20090827/ap_on_re_eu/eu_netherlands_not_moon_rock_3" :smile: http://d.yimg.com/a/p/ap/20090827/capt.97a493bc80a74af8bd49d6f1c24f68b3.netherlands_not_moon_rock_ams101.jpg?x=384&y=345&q=85&sig=.9mO0od3hiEuR5gaWQ_m0g--

I am constructing a few model airfoils for some low speed wind tunnel tests. I will be using wooden ribs covered in Mylar. I was just wondering what kind of wood is best for this situation: balsa, basswood, or a different kind of wood. Thank you

I am doing an experiment. For this experiment I am going to find out what has more effect on the height a block of wood will tip when pushed. I need some ideas on how to push the block of wood with the same force each time?

Homework Statement A 10g bullet is traveling at a speed of 1.5*10^2 m/s parallel to a horizontal surface when it strikes a 5.5kg wooden block. If the bullet becomes lodged in the block, how far will the block move along this surface? The coefficient of friction between the block and the...

You bought two kilograms of ice at -10 degrees celcius for your cooler when a friend suggests to instead use two kilograms of wood at -10 degrees celsius. Why should you stick with your ice? Thermal Conductivities Latent Heats Specific Heats Answer with either Good Reason, True but Irrelevant...

Homework Statement A rifle with a barrel length of 50.86 cm fires a 7.06 g bullet with a horizontal speed of 449 m/s. The bullet strikes a block of wood and penetrates to a depth of 12.9 cm. What resistive force (assumed to be constant) does the wood exert on the bullet? 5516.6785...

in my mind i am thinking smooth wood - more contact between object and surface - more friction rough wood - less contact b/t object and surface - less friction can someone explain why this is wrong; why rough wood has more friction? i know rough wood WOULD have more friction but need to...

Homework Statement A 2.37 kg wood block is launched up a wooden ramp that is inclined at a 35° angle. The block’s initial speed is 9.32 m/s. What vertical height does the block reach above its starting point? Homework Equations DYNAMICS 3. The Attempt at a Solution

1. Homework Statement [/b] A rifle with a barrel length of 61.54 cm fires a 8.17 g bullet with a horizontal speed of 400 m/s. The bullet strikes a block of wood and penetrates to a depth of 8.9 cm. What resistive force (assumed to be constant) does the wood exert on the bullet...

Hi, I am not sure if this belongs here and I apologize in advance if this has been placed incorrectly. Please move it to the appropriate forum. I have a Balsa bridge due in about 2 weeks. I have picked up the supplies but I am not sure how to start the process and I want to do it...

A block of wood of mass m1 = 0.15 kg slides to the right on a frictionless horizontal table with an unknown speed. It collides with a second piece of wood of mass m2 = 0.30 kg which is stationary and attached to a spring with a spring constant of k = 159.00 N/m. The two pieces of wood stick...

Homework Statement A 34.0 g bullet traveling at 122 m/s emdeds itself in a wooden block on a smooth surface. The block then slides toward a spring and collides with it. The block compresses the spring, k=99.0 N/m, a maximum of 1.20 cm. Calculate the mass of the block of wood. Homework...

Homework Statement When a piece of wood is pressed against a spring and compresses the spring by 4.00cm , the wood gains a maximum kinetic energy K when it is released. How much kinetic energy (in terms of K) would the piece of wood gain if the spring were compressed 20.0 cm instead? K_2...