Classical Physics & Particle Motion Under Force Field

In summary: Oh now I understand. If QM were to be applied here then the initial position and the velocity both specified in the question would render it meaningless. Thus, Newton's Laws can be used for the particle's motion. Thank you!
  • #1
warhammer
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Homework Statement
A particle of mass m moves under a force field corresponding to the potential energy V(x)=1/2kx^2 . It is given that at a certain instant t=0 , it is at x = 0 and its velocity is small and given by v=v0(i) . To get the subsequent motion,
(a) Newton’s laws of motion can be used
(b) Laws of quantum mechanics can be used
(c) This much data is not sufficient
(d) Laws of relativity must be applied
Relevant Equations
Given Potential Energy V(x)=1/2kx^2.
The particle is moving under a force field with the potential energy equation described above. I find it logical that Newton's Laws can be used as in the question itself it is stated that the velocity is quite small and we could approximate its subsequent motion via the notions of Classical Physics. Is my approach correct, because I also feel that being a single particle QM would come into play and consequently HUP which would make option (c) the correct one.
 
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  • #2
warhammer said:
Homework Statement: A particle of mass m moves under a force field corresponding to the potential energy V(x)=1/2kx^2 . It is given that at a certain instant t=0 , it is at x = 0 and its velocity is small and given by v=v0(i) . To get the subsequent motion,
(a) Newton’s laws of motion can be used
(b) Laws of quantum mechanics can be used
(c) This much data is not sufficient
(d) Laws of relativity must be applied
Homework Equations: Given Potential Energy V(x)=1/2kx^2.

The particle is moving under a force field with the potential energy equation described above. I find it logical that Newton's Laws can be used as in the question itself it is stated that the velocity is quite small and we could approximate its subsequent motion via the notions of Classical Physics. Is my approach correct, because I also feel that being a single particle QM would come into play and consequently HUP which would make option (c) the correct one.

How much do you know about QM?
 
  • #3
Quantum mechanics usually are applied for particles of the microscopic world, while classical physics for the macroscopic world. So what do you think is the criterion here to decide between a) and b) and do we have enough info about this criterion?
 
  • #4
PeroK said:
How much do you know about QM?
I have just started to understand the basics so I know very little.
 
  • #5
warhammer said:
I have just started to understand the basics so I know very little.

In QM you'd be given an initial wavefunction for the particle.

The HUP implies that being given the initial position and velocity is problematic for a quantum particle!
 
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  • #6
PeroK said:
In QM you'd be given an initial wavefunction for the particle.

The HUP implies that being given the initial position and velocity is problematic for a quantum particle!
Oh now I understand. If QM were to be applied here then the initial position and the velocity both specified in the question would render it meaningless. Thus, Newton's Laws can be used for the particle's motion. Thank you!
 
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1. What is classical physics?

Classical physics is a branch of physics that deals with the laws of motion and the behavior of matter on a macroscopic scale. It encompasses classical mechanics, thermodynamics, and electromagnetism.

2. What is particle motion under a force field?

Particle motion under a force field refers to the movement of particles in response to a force exerted on them by an external field. This can be seen in various phenomena such as the motion of planets in the solar system or the movement of charged particles in an electric field.

3. How do force fields affect particle motion?

Force fields can either attract or repel particles, causing them to move in a specific direction. The strength and direction of the force depend on the properties of the particles and the characteristics of the field. For example, gravity is a force field that attracts particles towards each other, while an electric field can either attract or repel charged particles.

4. What are some examples of force fields?

Some common examples of force fields are gravitational fields, electric fields, and magnetic fields. Other examples include nuclear force fields and fields created by moving charges, such as in electromagnetic induction.

5. How does classical physics explain particle motion under force fields?

Classical physics uses mathematical equations, such as Newton's laws of motion, to describe and predict the behavior of particles under force fields. These laws state that a particle will remain at rest or move with a constant velocity unless acted upon by an external force, and that the force is equal to the mass of the particle multiplied by its acceleration.

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