Rubber Definition and 242 Threads

Homework Statement Ideal rubber stirng with length L=1km.Ant is takng a walk on the string with speed v=1cm/s After every minute(Δt=60s) ,string is getting longer by ΔL=1km. 1)Will ant get to the end of string? 2)If yes,then how long it will take ? Homework Equations 1) So i used...

Some time ago, I came across this page on Wikipedia. The problem is interesting, and I understood it. There used to be a small part on the bottom that said something like 'One can stack a block, such that it overhangs off the table, and put more blocks on the first one to make the overhang...

Does anyone know where I can get those values? Haven't been able to find them anywhere

Homework Statement A cube of mass m is connected to two rubber bands of length L, each under tension T. The cube is displaced by a small distance y perpendicular to the length of the rubber bands. Assume the tension doesn't change. Show that the system exhibits SHM, and find its angular...

I have a rubber sample here, basically it is a slice with a diameter of 45mm and a depth of 3mm. If this sample was at 25 degrees Celsius and I applied 180 degrees temperature all around it (top, bottom faces and outside diameter) how long would it take for the centre point (last point to get...

Homework Statement Suppose a rubber ball collides head-on with a steel ball of equal mass traveling in the opposite direction with equal speed. Which ball, if either, receives the larger impulse? Explain. Homework Equations p = m*v impulse force = change in p The Attempt at a...

Homework Statement For the rubber band model, calculate the fractional change in (L-L0) that results from an increase δT in temperature, at constant tension. Express the result in terms of the length and temperature. Homework Equations U=cL0T τ=bT((L-L0)/(L1-L0)); τ=tension, L1=elastic...

By stretching a rubber band slowly and then slowly releasing it can we minimize the energy lost, (minimize the change in entropy?)? If so should a hysteresis curve be a function of the rate at which the rubber is deformed? See, http://en.wikipedia.org/wiki/Hysteresis#Elastic_hysteresis...

Do you know why it's important for rubber to be resilient? and does anybody have an example of an object that is made out of rubber which must be resilient? and does anybody know why it's important why tires and children's play grounds are made from resilient materials? Many thanks,

For example a phone in a case is dropped, would it suffer more in a plastic case or a rubber case? Thanks

Homework Statement Hi guys, I'm trying to solve questions from past exams; here comes one. There are 2 possible fundamental equations for the rubber bands: ##S=L_0\gamma \left ( \frac{aU}{L_0} \right ) ^{1/2} -L_0 \gamma \left [ \frac{1}{2} \left ( \frac{L}{L_0} \right ) ^2 + \frac{L_0}{L}...

Greetings, How can I derive the equation satisfied by a rubber sheet? I know that it reduces to Laplace's equation when the sheet is quite planar. I found the expression for it on p.113 in Introduction to Electrodynamics by Griffiths. Thanks in advance. Edit: I have attached the expression...

Homework Statement Please see attachment. Homework Equations The Attempt at a Solution Not really a homework problem. This is 1 of my exam question which I believe I had the right answer but my professor insists that he has the right one. I started by equating work done, W =...

Hello! I'm neck-deep in concept designs, and honestly, I am swamped. I'm participating in an experiment to launch a rubber stopper from a bottle using a gas-producing reaction. My most recent design structure used dry ice, and a chamber made of metal, with the dry ice proportioned out inside...

Homework Statement For a Science Olympiad project I need to make a rubber motored helicopter, and with this I need to find the best design for one. One special rule in this is that Chinook styled helicopters get 3x their original flight time, I was wondering if that would be just to encourage...

While sitting contemplating life today, I had a thought. Naturally were connected to the earth...The civilizations throughout history had a much deeper profound connection to it as well. The only difference besides technological advances is we wear shoes with rubber soles...Rubber is not...

Hey guys, I need to get some nitrile, latex, and rubber gum sheets for a project. The problem is, I need them to be really thin - 0.1 mm or thinner. And ideally, I would like to be able to pick what color I get. I spent a few days searching the web and not even Grainger has what I'm...

Does the spring constant of a piece of rubber affect its rate of cooling constant 'k' ? 1) Is there any formula, any proven relationship? 2) If there isn't, would investigating it make any sense? Or would it end up being a waste of time as the two variables are totally unrelated? Is there...

Homework Statement A 3 cm radius rubber ball weighing 5 g is used to plug a 4cm hole in the base of a tank. The tank is in use and is gradually emptying. At approximately what depth will the plug fail by floating up and out of the hole? Homework Equations Density The Attempt at a...

Interesting article from SciAm on transforming a rubberband into a trefoil knot and how math in the knot world of zero thickness says no but the real world says yes. http://www.scientificamerican.com/article.cfm?id=mathematical-impressions-can-you-turn-rubber-band-into-knot

Homework Statement Imagine a rubber beam. One en is fixed and the other is pulled down 5cm and released. The beam wobbles until it comes to rest. Independent (what I change): length of rubber beam Dependent (what I measure): time to come to rest Controlled (what stays the same)...

Just to be clear, this is NOT a homework question. It's honestly a question I have pondered for as long as I can remember sitting on the backseat of my family's minivan with a rubber ball. I'd also like to clear out that you bear with me and if I look unintelligent or questionably retarded...

Hello guys, I am calculating Bending and Shear stresses in hollow beams. We have a particular kind of shell that we use for impact loading, so we put rubber discs around the steel shell. So my question is, how will it affect the moment of inertia ? Since I know that the rubber discs will...

Rubber has roughly a stress of 1.0 MPa per unit strain . how much stress has been applied to the rubber band? Stress = f/a though it was straight forward and used the formula for stress but when I looked at the answer it was 2.0 x 10^6 Pa But why?

Need high-temp "rubber" coating Hey I'm looking to coat some 0.5" aluminum rods with some sort of coating to increase the friction coefficient ("tackiness" I believe it's called). It will be used in high temperature environments of up to 200C. Does anyone know of such product? I tried...

Okay, I am working on my physics lab, and I have a few questions regarding it. First, we are asked to make a prediction: "Predict how you think the presence of a rubber band will affect the force felt by the force probe from the rubber band compared to masses hung directly from the hook?" My...

Hello! Is there a metallic material that can have the elasticity properties of a rubber band? Thanks!

Need help in determining the impact force strength of a door stop rubber. It is a urethane rubber formed in a triangular shape. I used a 50t press with a 2" round shaft to compress rubber product and it required 100 lbs of force to compress. I believe this worked out to 18.75 ft lbs to...

Here is the problem: The bars of a saddle, which rest on a horse's back, rarely completely conform to the exact shape of the horse's back. I want to make a rubbery or heavy dense foam shim which will fill in the voids between the saddle bars and the horse's back so there is a perfect fit...

Hi guys I have a general query regarding Rubber O-rings. For an application , say seal between 2 mating flanges of pipes ,with water pressure say about 10bars, How exactly does the hardness of rubber effect the the sealing? Is there a direct relation between hardness & strength ? Can some...

Homework Statement [See Attachment] Given: Thickness, load, G Find:γ and horizontal displacement. Homework Equations τ=γG Angle change should be the shear strain. The Attempt at a Solution I tried plugging 800 into tau and the given value of G to get γ, but that isn't...

Homework Statement For a stretched rubber band, it is observed experimentally that the tension f is proportional tot he temperature T if the length L is held constant. Prove that: (a) the internal Energy U is a function of temperature; (b) adiabatic stretching of the band results in an...

I am trying to mount rubber wheels on a motor to make a paper airplane launcher similar to this: http://www.instructables.com/id/Super-fast-paper-plane-launcher/ only, instead of wheels, I'm using rubber stoppers (for flasks) I've got two questions, 1) how do I attach them to the motor...

Homework Statement Write a Java program to solve the following problem. An elastic rope starts out with length 100 meters. The start of the rope is fixed to a pole and a worm is placed on the rope at the start and the worm starts crawling towards the end. Each day the worm crawls 6 meters...

Hello everybody I have a mass production project for a new product . The thing is to be made in foam , sheets...it is some material involved . To visualize the idea think about the Yoga mat sort of material but much thick.. Natural or Synthetic ?..provided there is to be found a natural...

hi all can you please explain to me what a rubber tyre gantry is & how it works

Homework Statement Polymers, like rubber, are made of very long molecules, usually tangled up in a configuration that has lots of entropy. As a very crude model of a rubber band, consider a chain of N links, each of length l. Imagine that each link has only two possible states, pointing...

Hey I am doing an experiment, checking how the spring constant of a rubber band relates to the spring constant of rubber bands in parallel. I calculated the gradient of a F vs x, graph i got a -0.0853 for the first rubber band, -0.0791 & -0.088 for the 2nd and the 3rd. Then i did them in...

Hey I am doing a practical on the spring constant of a rubber band, we have studied hooke's law and from that found that the spring constant of a spring is well F = -kx so F is proportional to x. While i did the same experiment with a rubber band, hung it on a clamp connected to a retort...

Why a rubber band gets warmer when repeatedly stretched and relaxes? Where does the gained ME comes from? Besides, does rubber band obeys Hooke's Law?

I'm having difficulties in finding an answer to the issue show in the attached pic. Fracture surface on the failed bracket! I have the properties of the mild steel, the properties of the rubber mountings, and the number of the cycles per minute. What i can't figure out is the load or the force...

If you stretch a rubber band around a pole, the band exerts a force onto the surface of the pole (F1 in figure 1). Is it possible to calculate this force if I know the force needed to stretch the rubber band to the same total length as the circumference of the pole? That is to say: 1. I know...

ive heard somewhere that it is heat that does that, but the effect is supossed to be so small so that one can't even notice. and on the other hand the effect is so large that it resists the motion of your hand for example so something is clearly wrong here it can't be only heat can it it must...

Hi everyone. I want to heat a piece of Rubber by embedding copper strips or wires in it and passing electricity(120V - 2.5Amp) through it. The room temperature is 0(zero) deg Celsius and i want to heat the aluminum block(5" x 5" x 1") to 10 deg Celsius(Not more than 10 deg). Question...

Can somebody help me out? I a looking for a high temp rubber to use as a lamination press pad. Hopefully something over or around the 700 F (370 C) range. If you know of a material great... if you know of a supplier awesome. Thanks!

Homework Statement A 0.1 kg rubber ball and a 0.1 kg clay ball are both thrown at the wall with the same initial velocity. the rubber ball bounces, the clay ball sticks. Which exerts a larger impulse on the wall?

Homework Statement [FONT="Garamond"][SIZE="4"]A small explosive charge is placed in a rubber block resting on a smooth (frictionless) surface. When the charge is detonated, the block breaks into three pieces. A 200-g piece travels at 1.4 m/s, and 300g piece travels at 0.90m/s. The third...

Hello, I am looking for the most effective shape to pinch a rubber tube. The most effective shape requires the least force. Given a tube of certain diameter/thickness, I want to know whether I should use a flat, curved, knife edged or whatever type of pinch and what thickness it should...

Homework Statement Dear Yahoo Answers, Can someone please help me with this as it's driving me crazy! We had to complete an experiment where had to calculate the Young’s modulus of Rubber, by doing an experiment. So we used a rubber band and various weights to calculate the values, to...

Homework Statement Consider a rubber band for which the tension, f, as a function of temperature T and length L is f = \kappa T (L+\gamma L^2), where \kappa and \gamma are positive constants. Determine the heat flow between it and its surroundings when the rubber band is stretched reversibly...