Elastic Definition and 1000 Threads

The steel wire can withstand strong tensile stress, but when the steel wire is being coiled into a spring it can be an elastic spring. Why is this? Can this be proven mathematically?

Homework Statement An elastic wire has the folowing charcteristics:initial length l_0=60cm,section S=6mm^2,Young's Modulus E=\frac{12MN}{m^-2}.Initially the wire has both ends fixed. Its initial position is horizontal, untensioned. At the middle of the wire it's hanged a body that produces an...

When doing practice problems from my textbook, I often get confused with both of them. MOre specifically there are usually formulas which pertain to only one of those types of collisions. Ex: (v_1-v_2)_i = -(v_1-v_2)_f Does anyone know more of these types of formulas, or tricks to...

Homework Statement A ball of mass 100 g is projected straight up with a speed of 5 m/s from the floor. Another ball of mass 50 g is hung from the ceiling by a light string at a height of 1.00 m directly above the first ball, so that the projected ball collides elastically with it. Calculate...

Hello everyone, here we have two types of electron tunneling paths of electrons. as shown here, In an elastic tunneling the electron goes directly into metal2 with out falling to Fermi level of metal2..?? or Is it going to fallback by radiating its energy..??

Hi guys, I am trying to find the theoretical maximum elastic energy of a bow with a constant square cross section with its moment of inertia I, made from a homogenous material throughout the whole length so we can say that the Youngs modulus E is also constant. This bow is attached to a string...

Homework Statement A 67.6g tennis ball with an initial speed of 28.8m/s hits a wall and rebounds with the same speed. The figure below shows the force of the wall on the ball during the collision. What is the value of Fmax, the maximum value of the contact force during the collision, if the...

Hello Everyone, I'm trying to solve the following Problem: (taken from "SPH simulation for seismic behavior of Earth structures" - Y.Ono et. al) To this end, I wrote a small MATLAB skript, to be found here. The paper presents results at t=10s and t=20s: which my solution reproduces...

Ok.. So basically 100kg object V100 is coming from left to right at 20m/s and 50kg object V50 is coming from right to left at 35m/s and make collision. They get pushed away like on picture. I need to find V50 and V100 but from the looks of it, I need to find angle theta to find an answer. How...

Hi guys, I've been thinking on a problem for a while which really bothers me. I've been trying to mathematically solve the following problem: A train approaches the station at a velocity of V=50 m/s. Then a tennis ball is thrown with a velocity U=30 m/s, against the approaching train...

Homework Statement I was given the following problem and I an trying to discover if it can be answered by transforming to the center of mass frame and then transforming back. "Consider a perfectly elastic collision between a particle moving with kinetic energy 10 times its rest mass energy...

Hi All, I am reading the seminal paper by Eshelby on the elastic energy-momentum tensor, which I attach for your convenience. It is all beautiful but equation 4.4 at the beginning. He considers a surface S in the undeformed configuration of a body. The surface is translated by a vector u to a...

From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is initially negative then becomes positive above 30% of vital capacity when the lung volume increases from residual volume? What I initially thought...

Homework Statement A 0.2 kg block, moving at 6 m/s, is catching up and colliding elastically with a 0.6 kg block that is moving along the same line and in the same direction. Find the velocities of the ball after this one-dimensional collision. Homework Equations Conservation of...

A 1689 kg car collides head on with a 2000 kg truck. The collision is elastic. If the velocity of the truck is 17km/h in the same directions as the car's initial velocity, what is the initial speed of the car in km/h? I'm getting an answer but doesn't seem to make sense. So I'm...

Homework Statement A small ball of mass, ##m_1## is aligned above a larger ball of mass ##m_2=0.63kg##, with a slight seperation. The two are dropped simultaneously from a height ##h=1.8m##(Assume the radius of each ball is negligible relative to h.) (a) If the larger ball rebounds elastically...

Homework Statement I had a question regarding the elastic potential energy of a spring to the gravitational force of a cart. If you had a spring that was attached to the top of the inclined plane and to a cart with the cart moving downhill on an incline that was at an angle, how would...

Suppose that a mass M1 is moving with speed V1 and collides with mass M2 which is initially at rest. After the elastic collision they make, both momentum and kinetic energy are conserved. m_{1}v_{1f} + m_{2}v_{2f} = m_{1}v_{1i} \frac{1}{2}m_{1}||v_{1i}||^{2}=...

Homework Statement https://www.physicsforums.com/attachment.php?attachmentid=57592&stc=1&d=1365348538 I'm stuck at the second part, not really sure what to here to be honest. https://www.physicsforums.com/attachment.php?attachmentid=57590&stc=1&d=1365346819Homework Equations Usually the...

A 100gram block is attached to the end of a spring on a frictionless table that has a spring constant of 20N/m. The other end of the spring is attached to the wall. A 20g ball is thrown at the block with a velocity of 5.0m/s. If the collision is perfectly elastic, what is the ball's speed...

Homework Statement Hello everybody , a/There's an elastic collision between a photon of energy E and an electron at rest. After the collision, the energy of the photon is E/2 and propagates in a direction making an angle theta=60° with the initial direction. Find E. What kind of photon is this...

Homework Statement A 10.0 g marble slides to the left with a velocity of magnitude 0.400 m/s on the frictionless, horizontal surface of an icy New York sidewalk and has a head-on, elastic collision with a larger 30.0 g marble sliding to the right with a velocity of magnitude 0.200 m/s. Find...

Homework Statement A billiard ball moving at 5.40 m/s strikes a stationary ball of the same mass. After the collision, the first ball moves at 4.48 m/s at an angle of 34.0° with respect to the original line of motion. Assuming an elastic collision (and ignoring friction and rotational...

Hi, When we find out the deflection of beam, the factors considered are its geometry (moment of inertia) and young's modulus (E) of the material. As per text Hook's law 'E' is constant only till the elastic limit of the material. Assuming that the stress induced crosses the elastic limit, 'E'...

It is generally well known that the elastic modulus of most materials become larger with decreasing size. This could be due to decreased number of dislocations, surface effects etc. Does anyone know how exactly does this increase? Considering a ceramic or an oxide, how does the Elastic modulus E...

Homework Statement A 2kg block is resting on a frictionless table. It is hit, head on, by a 1kg block heading at 4 m/s. The larger block is sitting 3m from the edge of a 5m long table. The collision happens with the smaller block's distance being 2m from the table and the larger blocks d =...

Homework Statement The elastic form factors of the proton are well described by the form G(q2) = \frac{G(0)}{(1 + (\frac{q^{2}}{0.71})^{2}} with qw in GeV2. Show that an exponential distribution in the proton given by ρ(r) = ρoe-λr Homework Equations thought it to be the...

English is not my native language. My question is about what happens when we throw a ball on the floor. I understand why the ball bounces off it. But I have a question, I wonder why almost all the kinetic energy get back to the ball, rather than lost in the land, that is, why this energy is...

Homework Statement Ground-state hydrogen atom with 12 ev kinetic energy collides head-on with another ground-state hydrogen atom at rest. Using principles of conservation of energy and momentum, show that an inelastic collision cannot occur. Therefore the collision must be elastic...

Assume that a mass is attached to an elastic band and then allowed to oscillate. Would the formula for the period of oscillation be that as the same of the formula for the period of the oscillation for a spring. T=2∏(√m/k) ?

Homework Statement Hi! I have found an interesting statement. It says, that if we have a system of two masses and a wall (all collisions will be elastic ones) with one mass (lets label it as 1) trapped between the other mass (2) and the wall and if there is no friction, then if ratio of...

A linear elastic strip of natural length a and stiffness k lies between x = 0 and x = a. Each point on the strip is transformed by a differentiable, monotone increasing function f. a) Characterise the change in potential energy. b) Given the boundary conditions f(0) = 0 and f(a) = b, choose f...

(1)Block A of mass mA = 1kg is moving at velocity +v (from left to right) towards block B of mass mB = 2kg which is at rest. To the right of block B there is block C. It is at rest and its mass is mC = 1kg. Find the ultimate velocities of all three masses assuming all collisions are elastic...

Homework Statement A cue ball with speed U hits a stationary red ball of equal mass. The collision is elastic (ie no energy is converted into other forms). After the collision the cue ball is moving at an angle θ to its original path. Find the final speed of the cue ball. Homework...

Homework Statement Two identical ideal massless springs have unstretched lengths of 0.25m and spring constants of 700N/m. The springs are attached to a small cube and stretched to a length L of 0.30m. One spring on the left and one on the right. An external force P pulls the cube a distance of...

So the way we learned to solve elastic collisions is to use the center of mass reference frame. I calculated that the COM is moving at v=1.66 m/s relative to the lab frame. Next I calculated the velocity of the white ball to be +1.66 m/s relative to the COM frame and the black ball to have...

Homework Statement Consider a 2-D elastic collision between two masses. The first mass is moving at initial speed v0 towards the second mass. The second mass is initially at rest. Mass m1 = 0.1 kg and mass m2 = 0.2 kg. The first mass recoils at 30° above the horizontal at speed v1, and the...

I understand that in elastic scattering, the incident particle leaves the interaction with the same magnitude of momentum it had initially. But, can there also be a target particle recoil in this case? If the kinetic energy of the incident particle is conserved, how does the target particle...

Homework Statement A 5.0 kg block with a speed of 8.0 m/s travels 2.0 m along a horizontal surface where it makes a head-on, perfectly elastic collision with a 15.0 kg block which is at rest. The coecient of kinetic friction between both blocks and the surface is 0.35. How far does the 15.0...

I am participating in the IYPT and i have encountered a question on elastic space which relates to gravity wells. I need to get a proper hypothesis that can be investigated within realistic parameters. I unable to get any new ideas because i am relatively new to the subject and don't have much...

I am participating in the IYPT and i have encountered a question on elastic space which relates to gravity wells. I need to get a proper hypothesis that can be investigated within realistic parameters. I unable to get any new ideas because i am relatively new to the subject and don't have much...

Happy new year everyone, if I were to bungee jump off a building height H using a cord with an elasticity of 150 N/m 15 m long when it isn't stretched that is tied to a rope of length L (does not stretch), and I have a mass of M and the cord stretches X meters. Gravity is pulling at 10 m/s^2. I...

Hi guys, this is the equation of relative velocities in elastic collisions: Va1x-Vb1x = -(Va2x-Vb2x) I know that this means that the relative velocity of A to B before an elastic collision is the same in magnitude but opposite in direction after the collision. However, this applies only in the...

Homework Statement If a Mass let's say a Ball Bearing A with a velocity of 2ms-1 and a mass of 2Kg hits two other ball bearing B & C which is not moving with ball bearing B & C each has a mass of 1kg each. What will happen to ball bearing B & C? Please see attached picture i have the question...

Block 1 moves with speed of 10m/s to right. It hits block 2 which has twice the mass of block 1 and speed of 5m/s to right. compute the magnitude and direction of block 1 for a perfectly elastic collision. solution: u1 = 10m/s u2 = 5m/s m1v1 + m2v2 = m1u1 + m2u2 ----> v1 + 2v2 = u1 + 2u2 ...

Block 1 moves with speed of 10m/s to right. It hits block 2 which has twice the mass of block 1 and speed of 5m/s to right. compute the magnitude and direction of block 1 for a perfectly elastic collision. solution: u1 = 10m/s u2 = 5m/s m1v1 + m2v2 = m1u1 + m2u2 ----> v1 + 2v2 = u1 + 2u2...

Homework Statement A 2.0 kg ball moving with a speed of 3.0 m/s hits, elastically, an identical stationary ball. If the first ball moves away with an angle 30 degrees to the original path, determine the speed of the first ball after the collision, and the speed and direction of the second...

Homework Statement Two carts of equal mass (15 Kg) have a head on elastic collision. The first cart has a velocity of 18.5 m/s to the right, and the second has a velocity of 12 m/s to the left. What are the velocities of the two carts after the collision? Homework Equations Since it is...

Hey guys! I am currently developing a simulation that involves sphere (or if you like particle) collision in 3D space. And I want it to be accurate (on the level of classic mechanics). The algorithm to do the job would take in the velocities, masses and relative position (aka line of...

Hi, Homework Statement A square frame with a thin crust/layer of liquid with surface tension γ is given. Into the plane of the frame an elastic wire of circular shape with radius r_0 is inserted. The thin crust/layer of liquid is then burst (by pricking) and as a result of the force of...