Lecture6.pptx

# Lecture6.pptx - 1/24/11 PHYS360QuantumMechanics...

This preview shows pages 1–2. Sign up to view the full content.

1/24/11 1 PHYS 360 Quantum Mechanics Mon Jan 24, 2011 Lecture 6: If we make momentum an operator , will it agree with classical physics? Homework Set 2: Ch 1 ‐# 8, 9, 15, 17 IMPORTANT: Room change – move next door to Rm 331 Starts Wednesday. x = x Ψ x , t ( ) 2 dx −∞ + For par[cle in a given state, the expecta[on value for its posi[on is: Reminder: the expecta[on value is the average of repeated measurements on an ensemble of iden[cally prepared systems. How does <x> change with [me? Will this look like the velocity? d x dt = x t Ψ 2 dx = i 2 m x x Ψ * ∂Ψ x ∂Ψ * x Ψ dx We’ve used the results of last lecture’s deriva[on that the normaliza[on is constant. Should x be a func[on of [me? Integration by parts: f dg dx dx = df dx g dx + fg a b a b a b d x dt = x t Ψ 2 dx = i 2 m x x Ψ * ∂Ψ x ∂Ψ * x Ψ dx d x dt = i m Ψ * ∂Ψ x dx d x dt = i 2 m Ψ * ∂Ψ x ∂Ψ * x Ψ dx Now, integrate by parts again, but just on the second term: We will postulate

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/23/2011 for the course PHYS 360 taught by Professor Durbin,stephen during the Spring '11 term at Purdue University-West Lafayette.

### Page1 / 3

Lecture6.pptx - 1/24/11 PHYS360QuantumMechanics...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online