What is an elastic body?

Elasticity is the ability to deform, with complete reversibility - the ability to jump back into a shape or state equivalent to the applied force gradually deforms an object or body. One example of an elastic body that approximately meets this description is the pool cue ball, which after a collision with another billiards regains its original shape. Another example of the elastic body is spring or spandex belt. These will regain their shape after they have undergone compression or stretching. A continuous principle of physics is Hooke's law. For spring deformed along the x direction of his rest, Hooke's law is written f = -kx. Because it is comparable to the elastic body, when The Force is cut off, spring, if it is boundless, returns to the point of relaxation. If, on the other hand, the mass is attached to the spring, the object, when it is released, travels behind the relaxation point, oscillates back and forth until the internal friction ends the process. Objects in the real world can be easily pressed beyond elasticity.

When the elastic body collides with another elastic body, the deformations in both bodies are momentary and the kinetic energy is preserved. In such a collision, if both objects have the same mass and object #1 with speed V _{1 , the object #2 with speed at 2 , object no. A classic demonstration is a group of pendulums made of strings tied at the same point higher and connected to the metal balls of the same matter on the bottom, each touches the second. If the most pendulum is turned on the left, when it hits another ball, all its momentum is transferred to it, which is converted to the third when it hits it, and so on. Finally, you can see the last ball that moves to the right, with all the energy of the first pendulum; This exhibition is known as Newton's cradle.}

Further demonstration of elasticity is to bounce ivory balls on very harda dedicated surface that was wiped with oil. Ivory has an unusually high elasticity coefficient. The ball bounce almost almost to its earlier height and illustrates its minimal loss of kinetic energy in this process. The object, which is forced over its elastic limit, can show plastic deformation, and the changes are permanent. In metals, such permanent deformations often include atomic dislocations in a crystal matrix.