# Lect15 - PHYS 172: Modern Mechanics Fall 2009 Lecture 15 -...

This preview shows pages 1–7. Sign up to view the full content.

Fall 2009 PHYS 172: Modern Mechanics Lecture 15 - Multiple Particle Systems Read 8.1 - 8.5

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

View Full Document
Ch 1 Changes imply interactions Vectors are used to describe many changes Momentum is fundamental: p = γ m v . Ch 2 The momentum principle: Δ p = F Δ t Interactions correspond to forces . Use Δ r =( p /m) Δ t to predict future positions (position update formula) Review of What We’ve Covered Thus Far
Ch 3 Can use position update formula for variable forces too: Gravity Electric Reciprocity: These few principles were the basis for Exam 1. v F = " G Mm r 2 ˆ r r F = 1 4 "# o q 1 q 2 r 2 ˆ r r F 12 = ! r F 21 Review of What We’ve Covered Thus Far

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

View Full Document
Ch 4 Instantaneous (derivative) momentum principle, Spring F =-k s Δ x Mass-spring model of atoms, Y=k s /d. Speed of sound v~ ω d Analytic mass-spring solution: x(t)=Acos( ω t) Normal force, Tension force e.g. Circular Motion d r p dt = r F Principles Covered by Exam 2
Work simple particle: explain nuclear fission, fusion Potential energy = -(work by internal forces) (Multiparticle K+U can be viewed as increased mass in a single-particle model of the system) " W = v F # " r r W = v F ! d r r " E = " mc 2 = mc 2 + K U G = " G m 1 m 2 r U E = 1 4 "# o q 1 q 2 r U s = 1 2 kx 2 Chapter 5: The Energy Principle Δ E sys = W ext + Q

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

View Full Document
Δ E sys =W ext +Q Choice of system Energy accounting Dissipation, air resistance, friction… Damped Harmonic Oscillator, Driven Harmonic Oscillator
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 10/26/2009 for the course CHM 111 taught by Professor Staff during the Spring '08 term at Purdue University-West Lafayette.

### Page1 / 23

Lect15 - PHYS 172: Modern Mechanics Fall 2009 Lecture 15 -...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online