# Simple quantum mechanics operator question

1. Jan 31, 2012

### Chowie

1. The problem statement, all variables and given/known data

What physical quantity is represented by the operator $i\bar{h}∂/∂t$

2. Relevant equations

$i\bar{h}∂/∂t$

3. The attempt at a solution

It's a one mark question, I just have no idea what it is and I can't find it in my notes D:.

2. Jan 31, 2012

### Dick

Look at the Schrodinger equation.

3. Jan 31, 2012

### Chowie

Is it total energy for a free particle?

4. Jan 31, 2012

### Dick

The Schrodinger equation applies to more than just free particles. But yes, it's the Hamiltonian. So I think it would be fair to call it the energy.

5. Jan 31, 2012

### Chowie

Hmm, I have the hamiltonian written down here as

$\hat{H}=-\frac{\bar{h}^{2}}{2m}∂^{2}/∂x^{2}$

So that is also equal to $i\bar{h}∂/∂t$ ?

$\vec{}$

6. Jan 31, 2012

### Dick

That's the Hamiltonian for a free particle in one dimension. It's a special case. Your operator is the Hamiltonian even in cases where that is not the Hamiltonian.