Rubber band Definition and 66 Threads

I just baked a cake, and accidentally left a rubber band around the cake tin (which was holding the greaseproof paper in place). Is the cake inedible due to fumes given off by the rubber band?? Thanks :)

If you take a rubber band and fix it in a stretched position for an extended period of time, would it eventually lose its elasticity? If yes, then how can you calculate how long it would take until its elasticity decreases by a certain amount, say, fifty percent? If no, why not? How does the...

Nota that the path a to b is isothermal since J is proportional to L, then we can find the value of T_a and T_b using the equation of state and the figure. We have, \begin{equation} J_0=\alpha L_0T_b \end{equation} or \begin{equation} T_b=T_a=\frac{J_0}{\alpha L_0}=T_0 \end{equation} Also, by...

Hello, I am having trouble applying Lagrangian to this problem: A uniform thin circular rubber band of mass ##M ## and spring constant k has an original radius ##R##. Now it is tossed into the air. Assume it remains circular when stabilized in air and rotates at angular speed ##\omega## about...

why can't we use Cartesian coordinates and in which way to proceed?

Option (B) is wrong because energy should be received by rubber band when it is being stretched Option (D) is wrong because energy should be released by rubber band when it goes back to natural length The area between graph of stretching and contracting represents energy dissipated in rubber...

Maybe someone already did this experiment? We have rubber band stretched and attached to the fence of Marry Go Around. When Marry is not rotating we are oscillating rubber band vertically, and oscillation remains vertical. What would happen if we oscillate the rubber band vertically when Marry...

Summary: Looking of someone to double check my work on this design issue. I am posting this here because I am no longer a student, but it is similar to a simple homework problem Problem: I am designing a rubber-band like product for a client. He wants to take a durable rubber band and stretch...

I have an odd question after making a rubber band car. I'm wondering if placement of my pairs of wheels has any affect on how fast or how far my car goes. It seems to be a very impractical design, but I do want to know the science behind it. My question is if I move two wheels all the way to...

Homework Statement Let's put a ball in an empty space with a mass of 280 kg and a radius of 6 meters. Imagine that there is a rubber band around this ball. The initial radial extent of the rubber band is 2 meters. How can I determine the force that stretches the rubber band? And can i say that...

Homework Statement For a stretched rubber band, it is observed experimentally that the tension ##f## is proportional to the temperature ##T## if the length ##L## is held constant. Prove that: (b) adiabatic stretching of the band results in an increase in temperature; (c) the band will...

Hi all, I am working on a rubber band plane (something like this: http://www.instructables.com/id/Rubber-Band-Powered-Aeroplane/) and I got a question regarding to the physics on these plane. As there is only one propeller and one rubber band, when the rubber band untwist, why doesn’t it rotate...

I was reading the Feynman lectures and in one of the chapters on thermodynamics it is stated that stretching a rubber band makes its temperature rise. I feel like I understand the thermodynamics of the rubber band and yet this statement is puzzling me. I believe that when you stretch a rubber...

<Mentor's note: moved from a general forum and therefore no template> This is the equation of potential energy in rubber bands, however, I don't know how to calculate the inertia of the arm of catapults or get the k constant. And what does n mean? Basically, i don't understand the whole...

Homework Statement I did an experiment on how stretching a rubber band, affects the range or distance of a projectile shot. Variable list: Independent Variable Amount of stretching Dependent Variable Range or distance I created my catapults on my own and used two different rubbers bands...

Homework Statement A uniform thin circular rubber band of mass M and spring constant k has an original radius R. Now it is tossed into the air. Assume it remains circular when stabilized in air and rotates at angular speed ω about its center uniformly. Derive an expression for the new radius...

Stretching a rubber band increase its mass due to e=mcc, but how?

When I was 6 or 7 I decided to make a bow and arrow one day. I had never seen or handled one in real life, but it was intuitively obvious to me from TV that they way to do this was to tie the ends of a stretched rubber band to the ends of a stick. This would have worked, after a fashion...

i wanted to ask you that in c++it is important we should learn linked list before learning stack,queue that i wanted to know while studying data structures

Hello PF! I have a project/competition in freshman college Aerospace that calls for a plane that can stay in the air for as long a time as possible while going as far as possible. The requirements don't explicitly say we need rubber bands as a propulsion but pretty much prohibit everything but...

Homework Statement I need to explain for a lab, why the efficiency of a rubber band slingshot constant for different stretch lengths. I don't need math, just a general explanation of why kinetic energy of projectile/elastic potential energy in rubber band is constant. Homework EquationsThe...

Homework Statement Homework Equations $$ Z(1) = \sum_{i=1}^{} e^{\frac{E_i}{K_bT}} $$ where ##E_i## is each of the possible energy states available to a single link (in this case the right and the left states). $$ P=\frac{\sum_{i=1}^{} e^{\frac{E_i}{K_bT}}}{Z} $$ The Attempt at a Solution...

Homework Statement From the experiment I did my force was equal to 0.0686N +/- 0.00196N and my x (rubber band stretch) was equal to 0.003m +/-0.002. The question asks to determine the force constant k +/- ∆k. Homework Equations F = kx k = F/x ∆k = |k| ∆x/x +∆y/y The Attempt at a Solution k...

Homework Statement For a stretched rubber band, it is observed experimentally that the tension f is proportional to the temperature T if the length L is held constant. Show that: a) The internal energy U is a function of temperature only b) Adiabatic stretching of the band results in an...

Does this mean if I had a rubber band and weighed it, then stretched and weighed it while being stretched out, that it would weigh more at that time? Since at that time it has stored energy, which equates to mass?

Homework Statement "You have a 1 km long rubber band with one end attached to the wall, and the other in your hand. The bug begins to crawl towards you on the rubber band, starting from the wall, at a rate of 1 cm/sec. As he crawls the first centimeter you extend the rubber band 1 km; when he...

Hello i need to know what should i do, Consider i have a box, top half and bottom half. so now i have to hold the top half and bottom half together with the rubber band then how do i know what rubber band will be enough to exert force so that both parts of box are hold together. also i...

Homework Statement The equation of state for a rubber band with temperature T is \mathcal{F}=aT\left[\frac{L}{L_0}-\left(\frac{L_0}{L}\right)^2\right] Where \mathcal{F} is the tension, L is the stretched length and L_0 is the unstretched length a) Write the Central Equation for the...

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...

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}...

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 =...

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 A person performs an exercise where he pulls a rubber band stuck in a wall to later return it to its resting position. The two movements forward and backward, is equivalent to one practice cycle. They both happen in a horrizontal plane with a constant velocity of v=0.5ms-1...

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...

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...

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...

1. i have a physics project where we have to make a car that accelerates the fastest during 3.0 m. it also must be accelerating for the whole 3.0m. I am using a simple rubber band car where the rubber bands are attached to both axels and are wound up. i have to make a bunch of calculations but...

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?

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...

Homework Statement In class we studied a phase transition in a model of a rubber band. For small applied tensions, f < f^*, the Helmholtz free energy of the band as a function of the length is A_1(L) = (\kappa_1 /2)L^2, while at large applied tensions, f > f^*, it is A_2(L) = (\kappa_2 /2)L^2...

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...

okay guys I've been looking for ages and i just can't find anything that will help me with finding a distance that will be travel by a rubber band powered car. I've been playing around with kinetic energy= potential energy but i can't seem to get anywhere. Any help will be greatly appreciated...

Hmm...some experimenting led to an interesting result. I attached a weight to a rubber band and suspended the rubber band in some hot water. The rubber band expanded. I repeated the experiment in cold water and the band shrank. An expected result, yes? Well I redid the experiment in air and I...

Hi, Not sure if I'm asking this in the right place, but I was wondering about the energy stored in a rubber band for a physics project I am working on. We all know that for a spring or rubber band being extended, the restoring force is given by F=-kx, and the energy stored U=0.5kx2. However...

[b]1. The problem: Suppose a rubber band obeys the equation of state: L = f (b/T), where L is length, f is tension, b is a constant, and T is temperature. For this rubber band, determine (δC[SUB]L/δL)[SUB]T, i.e. the change in the constant length heat capacity with length at constant...

Do I understand this?-if I stretch a rubber band from a 1" length to a 2" length... If I stretch a rubber band from a 1" length to a 2" length, is it true that it was not all possible lengths between 1" and 2" sometime during the stretch? In other words, at some level, quantization enters in...

In the text, there is a rubber band model for 1D chain of N links. Assume each link of the rubber band is align horizontally either to the right or to the left. In the text, define N_+ as the number of links directed to the right and N_- represents the number of links directed to the left. I...

Suppose we have a rubber band of some elasticity k and of unstreched radius r0 (the band is always kept in the shape of a circle). What work is necessary to strech it to some larger radius r? How do we apply Hooke's law in this situation? Thanks

I have a project that I'm working on involving a rubber band powered vehicle. I have a pretty well developed design involving several methods of propulsion but my main concern is a trigger mechanism in which to release this source of power from the rubber bands. Im not sure whether to go...