- What is elasticity in physics?
- Formula of elasticity in physics
- Examples of elasticity in physics
- Elastic materials
We explain what elasticity is in physics and what the formula for this property is like. Also, examples and elastic materials.
What is elasticity in physics?
When inphysical We speak of elasticity, we refer to the property of certain materials to be deformed under an external force that acts on them and then recover their original shape when said force disappears. These types of behaviors are known as reversible deformations orshape memory.
Not all materials are elastic and those that break, fragment or remain deformed after the action of the force external are just not elastic at all.
The principles of elasticity are studied by the mechanics of deformable solids, according to the Theory of Elasticity, which explains how a solid it deforms or moves in response to external forces that affect it.
Thus, when these deformable solids receive said external force, they deform and accumulate an amount of elastic potential energy and, therefore, internal energy within them.
Said energy, once the deforming force has been removed, will be the one that forces the solid to regain its shape and transform into Kinetic energy, making it move or vibrate.
The magnitude of the external force and the coefficients of elasticity of the deformed object will be those that allow calculating the size of the deformation, the magnitude of the elastic response and the accumulated stress in the process.
Formula of elasticity in physics
When a force is applied to an elastic material, it deforms or compresses. For the mechanics, the important thing about the fact is the amount of force applied per unit area, which we will call effort (σ).
We will call the degree of stretching or compression of matter deformation (ϵ) and we will calculate it by dividing the length ofmovement of the solid (ΔL) by its initial length (L0), that is: ϵ = ΔL / L 0.
On the other hand, one of the main laws that governs the phenomenon of elasticity is theHooke's law. This law was formulated in the seventeenth century by physicist Robert Hooke when he studied a spring and realized that the force necessary to compress it was proportional to the variation in its elongation when applying said force.
This law is formulated as follows: F = ˗k.x where F is the force, x the length compression or elongation, and k a constant of proportionality (spring constant) expressed in Newtons over meters (N / m).
Finally, thepotential energy Elastic associated with the elastic force is represented by the formula: Ep (x) = ½. k.x2.
Examples of elasticity in physics
The elasticity of materials is a property that we test daily. Some examples are:
- Springs The springs that are under certain buttons, or that push the bread from the toaster up when it is ready, operate on the basis of elastic tension: they are compressed and accumulate potential energy, then they are released and regain their shape by throwing the bread up. toasted.
- Buttons. The buttons on the remote control of the television operate thanks to the elasticity of the material that compose them, since they can be compressed under the force of our fingers, activating the circuit that is underneath, and then recovering their initial position (not activating the circuit immediately ), ready to be pressed again.
- The gum. The resin from which gum or chewing gum is made is extremely elastic, to the point that we can compress it between the teeth or expand it by filling it with air and making a bomb, assuming that it will retain its more or less original shape.
- The tires. An airplane, a car, a motorcycle, operate based on the elasticity of the rubber, which once inflated with air, it can withstand the enormous weight of the entire vehicle and deform slightly, but without losing its shape memory, thus exerting a endurance and keeps the vehicle suspended.
Elastic materials
Elastic materials, those capable of recovering their original shape after suffering partial or total deformation, are numerous: rubber, rubber, nylon, lycra, latex, chewing gum, wool, silicone, foam rubber, graphene, fiberglass, plastic, rope, among others.
These materials are extremely useful in the manufacturing industry, since from them a myriad of applications and objects of practical use can be made.