# Mechanical descriptions of particles

• Pjpic
In summary, string theory has introduced a new way of describing particles as vibrations of extended strings, avoiding the infinities associated with traditional mathematical descriptions of behaviors. This concept also allows for the possibility of quantum confinement and the application of the Pauli exclusion principle.

#### Pjpic

Has string theory changed the practice (if it actually was the practice) of describing particles with equations of behaviors instead of as actual objects (like points or maybe strings).

No such practice. probably more typical to think of as "mathematical description of particles"
Particles are not described in either/or fashion as you suggest. String theory describes particles as vibrations of extended strings; charge manifests as one type of vibration, mass as vibrational energy, and so forth.

The extended nature of such "particles" avoids the infinities assoicated with mathematical descriptions of behaviors assoicated with point particles. Coulombs law for example, kq1q2/r2 becomes infinite as the distance between two charges apporaches zero. Doesn't quite seem that two finite charges would repel at infinite force in a classical theory. On the other hand quantum confinement of such particles might conceivabley produce incredibly powerful repulsion, but that's where quantum theory may not work so well either...The Pauli exclusion principle can cover a situation like that.

## 1. What is the difference between mass and weight in mechanical descriptions of particles?

Mass refers to the amount of matter in a particle, while weight refers to the force of gravity acting on the particle. Mass is a constant property, while weight can vary depending on the gravitational pull of a particular location.

## 2. How do mechanical descriptions of particles relate to the laws of motion?

The mechanical descriptions of particles are based on Newton's laws of motion, which describe the relationship between an object's mass, acceleration, and the forces acting upon it. These laws help us understand and predict the behavior of particles in motion.

## 3. What is the significance of velocity and acceleration in mechanical descriptions of particles?

Velocity and acceleration are important parameters in mechanical descriptions of particles as they determine the motion of the particle. Velocity refers to the rate of change of an object's position, while acceleration refers to the rate of change of its velocity. These values help us calculate the trajectory and speed of a particle.

## 4. How do we measure and quantify forces in mechanical descriptions of particles?

Forces are measured using a unit called Newtons (N) in mechanical descriptions of particles. A force is a push or pull that can cause an object to accelerate or change direction. The magnitude of a force is determined by the mass and acceleration of the particle.

## 5. Can mechanical descriptions of particles be applied to systems with multiple particles?

Yes, mechanical descriptions of particles can be applied to systems with multiple particles. The laws of motion and principles of mechanics can be used to analyze the behavior and interactions of multiple particles in a system, such as in a gas or fluid.