It follows from the Expectation value postulate that an observable A, associated with the operator A^, can be precisely measured only if the wave function ψ of the system is an eigenfunction of A^ .
Accordingly, the position and momentum of a particle can never be precisely measured because...
Homework Statement
The potential energy (V) of a conservative system is a function of position (q) only. Thus, V = V(q) for any conservative system.
When a conservative system interacts with radiation (spectroscopy), then the PE of the system depends explicitly on time (t) also: V =...
Pl. see the following calcultions and advise me on the error involved:
(1) I consider a Cart coordinate system (drawn as per the right hand thumb rule) with +ve Z axis pointing upwards. Now, consider a body falling from z=h to z=0. The work involved is:
Integral (from h to 0) of [-mg dz]...
When a body falls from a height (h) under gravity,the work involved is mgh. How do you describe this work? Is it 'work done by the force (gravity) on the body' or 'work done by the body'. The confusion is, if work is done on the body the body gains energy; but if work is done by the body the...
In physics at university, I was told that quantum mechanics was based on a number of postulates, two of which were:
1. For every particle moving in a conservative field of force there exists an associated wave function, psi, which determines every property which can be physically measured. In...
Re: Operator Equation
2. To every physical observable O, there exists an associated operator O such that Opsi = o*psi, and this equation is solvable for o and a corresponding value of psi.
The above postulate (such that Opsi = o*psi,) gives an impression that the wave function of a system is...
2. To every physical observable O, there exists an associated operator O such that Opsi = o*psi, and this equation is solvable for o and a corresponding value of psi.
Is it right to state that "such that Opsi = o*psi, and this equation is solvable for o and a corresponding value of psi"?. I...
A mathematical operator (Aop) operates on a function (f) to generate a new function (f '):
Aop (f) = f ' (1)
Consider that I subtract a from b to get c:
b-a = c (2)
Can I write this subtraction operation as an operator equation of the form (1) as shown below?
(-a) (b) = c...
It is possible to deduce the time-energy uncert. relation from the "true" position-momentum uncert. relation as many books show:
For a free particle, E=p^2/2m. So, the error in the measurement of the energy is
dE = p/m dp (1)
where dp is the error in the measurement of momentum...
I am a chemistry student. We use this energy-time uncertainty quite a lot especially in spectroscopy and it works and explains. This relation explains tunneling also. So I do believe that this uncertainty relation is quite genuine.
According to the operator postulate of Quantum Mechanics, the...
I think it is a good idea to refer to the internal energy of a system and then fix the sign of work and heat. Usually, a system changes from one state to another state by exchanging heat and work (two different forms of energy) with the surroundings.
Heat supplied to the system increases...