Elastic Definition and 1000 Threads

Hi everyone! Please help, I have spent a considerable time to understand the two concepts and still this is nagging at me... I am relating to Structural Engineering, just to let you know guys. My question is .. Moment of inertia is about distribution of mass, the further away from the axis the...

Hi guys. There is a question that confusing me for a long time. If an elastic collision occur, do I need to consider the positive and negative sign?? According to my teacher, an object moves in the opposite direction we need to consider the sign. Is it works in this situation?

Homework Statement A 2D elastic collision: Two pucks (masses m1 = 0.5 kg and m2 = 0.3 kg) collide on a frictionless air-hockey table. Puck 1 has an initial velocity of 4 m/s in the positive x direction and a final velocity of 2 m/s in an unknown direction, θ. Puck 2 is initially at rest. Find...

http://imgur.com/oLMkHBX How exactly would you calculate E in this? The cross section is a square and it deforms .8 mm. I'm not quite sure what to do since obviously the size of the cross section changes.

Homework Statement Three perfectly elastic particles A, B, C with masses 4 kg, 2 kg, 3 kg respectively, lie at rest in a straight line on a smooth horizontal table. Particle A is projected towards B with speed 15 m/s and after A has collided with B, B collides with C. Find the velocities of the...

Homework Statement [/B] A cylinder with mass 3kg slides on ice with its base surface at 5m/s and collides with an identical but stationary cylinder. The collision is elastic. After the collision, the center-masses of the cylinders move at angles 45 and 30 degrees from the starting direction...

Hi, I have a balloon filled with glass beads (exercise-stress ball). When I squeeze the balloon, it changes its shape. Let's assume the initial shape is a sphere with radius R0 and thickness h0 and the final shape is like a pancake (cylinder R1 + half torus R2 with thickness h1). Can you help me...

Homework Statement A low-energy particle collides elastically with a stationary particle of the same mass. The angle between the subsequent paths of both particles are 90 degrees. But when a high-energy proton collides with a stationary proton, the angle between the two paths is not 90 degrees...

Homework Statement The problem is pretty simple, however I don't understand which value to use after using quad formula to solve. See below. V1(initial) = 2.5 m/s V2(Initial) = -5.9 m/s A pool ball moving with a speed of 2.5 m/s makes an elastic head-on collision with an identical ball...

Hey there, I'm struggling in finding the useful equations to determine some conformability parameters for a finite elastic material (EPDM) compressed on a rigid slightly wavy surface. I would like to optimize the thickness of the elastic material in terms of indentation depth and thus contact...

Homework Statement A 15.0 kg stone slides down a snow-covered hill leaving point A (at the top of the hill) with a speed of 10.0 m/s. There is no friction on he hill between point A and point B (at the foot of the hill). There is friction on the level ground at the bottom of the hill between...

This is the problem I am looking to solve: given two objects of different mass, find the angle of deflection after an elastic collision for each object. For both objects we know: m : Mass in Kilograms θi : Initial Angle in Degrees si : Initial Speed in Units per Second sf : Final Speed in...

Homework Statement A curling stone with initial speed vi1 collides head-on with a second, stationary stone of identical mass, m. Calculate the final speeds of the two curling stones. Homework Equations See attached picture The Attempt at a Solution I solved for vf1 as shown, but my answer...

Homework Statement Two balls collide in a perfectly elastic collision. Ball 1 has a mass of 3.5kg and is initially traveling at a velocity of 5.4m/s. It collides head-on with stationary ball 2 with mass 4.8kg. Determine the final velocity of ball 2. Given: m1=3.5kg vi1=5.4m/s m2=4.8kg...

NO TEMPLATE BECAUSE THREAD WAS STARTED IN WRONG FORUM A wrecking ball is a heavy steel ball, usually hung from a crane that is used for demolishing large buildings. Suppose we had a crane with a wrecking ball with a mass of m1 = 12,000 lbs. The crane produces a displacement on the ball of a...

Hello, I would expect the heating of an elastic material upon sudden elastic compression to be given simply by the first law of thermodynamics, i.e. Delta Q=Delta U + P Delta V where P is constant since the compression is applied suddenly as in a square-wave pressure pulse (this is equivalent...

Homework Statement If a object 1 & 2 collide as a perfectly inelastic collision, would they will both stop. Also If this same situation happened elastic? please explain if this is true or false and draw a free body diagram if possible. Homework Equations F=ma Newton second Law KE=1/2ma The...

Homework Statement 2 balls, their size is the same but mass is different, they are going towards a collision. I do not know what is the word for it in english but its like this m1= 1,2m2. Speed of the balls are v1=12m/s and v2= 15m/s.Calculate the speed of each ball after absolutely central...

Homework Statement Two masses A, and B both sit on a vertical spring. If the spring is compressed then released, why do A and B rise to the same height? (the mass of A is greater than that of B) Homework Equations P = mgh S = 1/2kx2 K = 1/2mv2 The Attempt at a Solution Both masses rise to the...

Hi. I've set myself a project with a couple of my classmates and despite the impracticability of it we want to do it as well as possible. Our aim is to look at using a massive elastic band in order to launch a payload at massive velocities, possibly even at escape velocity. To this end I've...

Hi all. Our lecturer gave us an exercise the other day regarding an elastic gravitational collision between a planet and a satellite where the satellite slingshots using the gravitational field of the planet. The question asks to show that ##v_{f} - v_{i} = 2v_{0}## where ##v_{f}## is the final...

1. Homework Statement For part (iii) , I used the principle of conservation of energy, K.E of the 2 kg particle after collision + E.P.E = K.E of the 2 kg particle at the furthest distance away from A + E.PE, But the solution for this question did not include the E.P.E of the string...

Homework Statement I figured out the first part of the question, proving why |t| equals 1, but I have trouble solving the next part of the problem. I expressed F(r(s)) in terms of theta, but I cannot solve for a, b, and c using the equation I derived. 2. Homework Equations Free energy...

Homework Statement The 80kg Tarzan swings from a 3m vine that is horizontal when he starts. At the bottom of his arc, he picks up 60kg Jane in an ELASTIC collision. Find max height they reach together. 2. Relevant equation Wgrav= mgy1-mgy2 Wel=.5k(xi^2-xf^2) The Attempt at a Solution I have no...

Homework Statement So I have just studied this topic and it seems a bit confusing to me. Lets just say we have elastic collision, Why sometimes both of the objects move at the same speed? and sometimes if one object is stationary and the other object hits it ( They have the same mass) why does...

Homework Statement A ball of mass m rolls down a 3.0 m ramp inclined at 30° above the horizontal, rolls along a flat, friction less surface, and collides elastically with another ball of mass 2m, initially at rest. The second mass then moves along the surface and collides with a horizontally...

Homework Statement In a closed system, in an inelastic collision, momentum and total energy is conserved, but total kinetic energy is not. But how is this possible? If we have a change in total kinetic energy, we have a change in velocity, and so we must have a change in momentum as...

Homework Statement Problem: An object of mass m1 elastically collides with an object of mass m2 =(3/2) m1 that is initially at rest. The less massive object has speed v1 and travels at an angle of θ1with its original direction (x-axis) after collision; the more massive object has a speed of v2...

Homework Statement You have an inertia of 52 kg and are standing at rest on an iced-over pond in your skates. Suddenly, your 60-kg brother skates in from the right with x component of velocity -4.9 m/s and collides elastically with you. 1. What is the siblings' relative speed after the...

Homework Statement Two objects collide and bounce off one another. After the collision, object m1 = 2.74 kg moves off at 12.8 m/s at a heading of 295 degrees. Object m2 = 2.28 kg moves off at 12.8 m/s at a heading of 241 degrees. Initially, m2 was traveling at 11.1 m/s at a heading of 334...

Hi everyone. I've a question that i wondered since the high school. Let's take two identical particles (same mass) that collide frontally. Assume it's an elastic collision. We have to conservate both the momentum and kinetic energy: v_1 + v_2 = v'_1 + v'_1 v^2_1 + v^2_2 = v'^2_1 + v'^2_1...

Homework Statement Consider a spring of natural length L_0 with constant k which rests on a horizontal frictionless surface. The spring is attached at one end to a fixed post and at the other end to a mass m. Suppose the spring is rotating around the post in a circle with angular velocity w...

Homework Statement Consider a frictionless track as shown (I will attach an image in a follow up post). A block of mass M1= 5.00 kg is released from point A. It makes a head-on elastic collision at B with a block of mass m2 = 10 kg that is initially at rest. Calculate the maximum height to...

Hello--can anyone please help me estimate the PSI required in an air mattress to minimize or even prevent displacement if a person, say 220 lbs, walked across it? Mattress material and wall thickness variable. Surface area variable. Also, if scenarios where the person is standing still...

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 angle 30° to the original path, determine: a. the speed of the first ball after the collision. b. the speed and direction of the second ball after...

Hi all, I've been self-studying a first year uni introductory mechanics course, and I'm confused with the derivations involved in calculating the final state of an elastic collision in one dimension, given the initial state. So basically we have masses of m_1, m_2 with initial velocities v_1i...

Homework Statement hello! so i am trying to figure out how to calculate the resultant velocities and directions(angles/vectors) that two perfectly elastic spheres might travel in if they were to be hit simultaneously by a third sphere at an angle. all the spheres are of equal mass, initial...

Hi, About elastic and plastic materials: All materials exhibit elastic deformation up to a certain limit, beyond which they exhibit plastic deformation. Some materials, such as plasticine, have extremely tiny elastic regions, so we call them 'plastic materials'. Some, like rubber, have large...

Homework Statement So this is just something i came up with to check if i am understanding everything allright, it all comes down to collisions in regard to the center of mass So two "masses" experience a glancing collision M1: vi - 3m/s (refered to as v1i) ; m - 2Kg (m1) M2...

1. The problem statement, all variables and given data A mass hangs in balance on a elastic rope (k= 800 N/m). The length of the rope in balance is 1m. They pull the mass 25 cm out of balance. The mass colides with the ceiling (restitution coefficient = 0,8). How far extend the rope after the...

Homework Statement Two 1.0-kg carts are coupled together and placed on a very long horizontal track that is at rest in the Earth frame of reference. The combination is launched so that at t = 0 it is moving to the right at speed 2.0 m/s in the Earth frame, with cart #1 in front and cart #2 in...

Homework Statement A red and a blue rubber puck are free to slide along a frictionless air table. Each has a mass of 40 grams. They collide in an elastic collision. Initially the red one is at rest and the blue one is traveling in the x direction with a speed of 4 m/s. After the collision the...

Homework Statement Consider the following head-on elastic collision. Particle 1 has rest mass 2mo, and particle 2 has rest mass mo. Before the collision, particle 1 movies toward particle 2, which is initially at rest, with speed u (= 0.600c ). After the collision each particle moves in the...

Homework Statement When an alpha particle collides elastically with a nucleus, the nucleus recoils. Suppose a 3.94 MeV alpha particle has a head-on elastic collision with a gold nucleus that is initially at rest. What is the kinetic energy of (a) the recoiling nucleus and (b) the rebounding...

Homework Statement [/B] Person A fires a 222 g arrow towards an archery target at a speed of 109 m/s. Person B shoots a 190. g arrow moving in the same direction. This arrow moves with a speed of 290. m/s, catches up, and then collides with Person A's arrow. If the arrows collide in a...

Homework Statement Hi there! In this exercise, we are supposed to derive this formula for a 2-D elastic with two different masses: (x-U*v1)^2 + y^2 = (Uv1)^2 (example, two billiard balls), the second mass is at rest. It's a equation which leads to a circle where all of the possible p2' lie...

Homework Statement A car whose mass is 2000 kg moves with a velocity of 30 m/s. It hits a stationary car that has the same mass. (Ignore all horizontal forces except for the ones that two cars exert on each other.) a) The two cars stick to each other after the collision. What is their velocity...

Homework Statement A red ball and blue ball are sliding on a frictionless surface, each ball has a mass of 40g. They collide in an elastic collision. Initially the red one is at rest and the blue one is traveling in the x direction with a speed of 4 m/s. After the collision the blue one is...

Homework Statement See picture Homework Equations p = p1 +p2 p = mv The Attempt at a Solution See picture, using equations for the velocity and using 90-tan-1(2) for the angle

Imagine you have an object of, say, 5kg moving in the positive x direction at 2m/s. So it has 10kgm/s of momentum. Now imagine an elastic collision from the y direction that gives the object another 10m/s in the positive y direction. Therefore its momentum doubles. Now we know that the...