f06 wk10

Information about f06 wk10

Published on January 4, 2008

Author: Maitane

Source: authorstream.com

Content

Chapter 12: Equilibrium and Elasticity:  Chapter 12: Equilibrium and Elasticity Conditions Under Which a Rigid Object is in Equilibrium Problem-Solving Strategy Elasticity Equilibrium::  Equilibrium: Conditions of Equilibrium::  Conditions of Equilibrium: Net force: Net torque: Conditions of equilibrium: Another requirements for static equilibrium: The center or gravity::  The center or gravity: The gravitational force on a body effectively acts at a single point, called the center of gravity (cog) of the body. the center of mass of an object depends on its shape and its density the center of gravity of an object depends on its shape, density, and the external gravitational field. Does the center of gravity of the body always coincide with the center of mass (com)? Yes, if the body is in a uniform gravitational field. How is the center of gravity of an object determined?:  How is the center of gravity of an object determined? The center of gravity (cog) of a regularly shaped body of uniform composition lies at its geometric center. The (cog) of the body can be located by suspending it from several different points. The cog is always on the line-of-action of the force supporting the object. cog Problem-Solving Strategy::  Problem-Solving Strategy: Define the system to be analyzed Identify the forces acting on the system Draw a free-body diagram of the system and show all the forces acting on the system, labeling them and making sure that their points of application and lines of action are correctly shown. Write down two equilibrium requirements in components and solve these for the unknowns Slide7:  Sample Problem 12-1: Define the system to be analyzed: beam & block Identify the forces acting on the system: the gravitational forces: mg & Mg, the forces from the left and the right scales: Fl & Fr Draw a force diagram Write down the equilibrium requirements in components and solve these for the unknowns Elasticity:  Elasticity Some concepts: Rigid Body: Deformable Body: elastic body: rubber, steel, rock… plastic body: lead, moist clay, putty… Stress: Deforming force per unit area (N/m2) Strain: unit deformation Young’s Modulus: Elasticity in Length:  Young’s Modulus: Elasticity in Length The Young’s modulus, E, can be calculated by dividing the stress by the strain, i.e.     where (in SI units) E is measured in newtons per square metre (N/m²). F is the force, measured in newtons (N) A is the cross-sectional area through which the force is applied, measured in square metres (m2) L is the extension, measured in metres (m) L is the natural length, measured in metres (m) Slide10:  Table 12-1: Some elastic properties of selected material of engineering interest Shear Modulus: Elasticity in Shape:  Shear Modulus: Elasticity in Shape The shear modulus, G, can be calculated by dividing the shear stress by the strain, i.e.     where (in SI units) G is measured in newtons per square metre (N/m²) F is the force, measured in newtons (N) A is the cross-sectional area through which the force is applied, measured in square metres (m2) x is the horizontal distance the sheared face moves, measured in metres (m) L is the height of the object, measured in metres (m) Bulk Modulus: Elasticity in Volume:  Bulk Modulus: Elasticity in Volume The bulk modulus, B, can be calculated by dividing the hydraulic stress by the strain, i.e.     where (in SI units) B is measured in newtons per square metre (N/m²) P is measured in in newtons per square metre (N/m²) V is the change in volume, measured in metres (m3) V is the original volume, measured in metres (m3) Summary::  Summary: Requirements for Equilibrium: The cog of an object coincides with the com if the object is in a uniform gravitational field. Solutions of Problems: Elastic Moduli: tension and compression shearing hydraulic stress Define the system to be analyzed Identify the forces acting on the system Draw a force diagram Write down the equilibrium requirements in components and solve these for the unknowns Slide15:  Sample Problem 12-2: Define the object to be analyzed: firefighter & ladder Identify the forces acting on the system: the gravitational forces: mg & Mg, the force from the wall: Fw the force from the pavement: Fpx & Fpy Draw a force diagram Write down the equilibrium requirements in components and solve these for the unknowns Sample Problem 12-3::  Sample Problem 12-3: Slide17:  Write down the equilibrium requirements in components and solve these for the unknowns Balance of forces: Balance of torques: Slide18:  Sample Problem 12-6: Define the system to be analyzed: table plus steel cylinder. Identify the forces acting on the object: the gravitational force (Mg), the forces on legs from the floor (F1= F2= F3 and F4). Slide19:  Write down the equilibrium requirements in components and solve these for the unknowns Balance of forces: If table remains level:

Related presentations


Other presentations created by Maitane

Introduction DFT
16. 10. 2007
0 views

Introduction DFT

ch04 org cell
08. 05. 2008
0 views

ch04 org cell

taylor forcefeedback
08. 05. 2008
0 views

taylor forcefeedback

lecture01
07. 05. 2008
0 views

lecture01

majumdar iccs05
02. 05. 2008
0 views

majumdar iccs05

accident causation
02. 05. 2008
0 views

accident causation

452 lecture9
02. 05. 2008
0 views

452 lecture9

JohnAdamCAS
02. 05. 2008
0 views

JohnAdamCAS

v1exploratorium
02. 05. 2008
0 views

v1exploratorium

Ode to a rat
03. 10. 2007
0 views

Ode to a rat

crocodile physics
11. 10. 2007
0 views

crocodile physics

Critical Thinking
12. 10. 2007
0 views

Critical Thinking

Lectures 2
16. 10. 2007
0 views

Lectures 2

USLA
22. 10. 2007
0 views

USLA

Typologie etudiants 2005 2006
24. 10. 2007
0 views

Typologie etudiants 2005 2006

Land Ho The Isthmus Forms
25. 10. 2007
0 views

Land Ho The Isthmus Forms

Nobelpreis 2004
15. 10. 2007
0 views

Nobelpreis 2004

city sadness
01. 11. 2007
0 views

city sadness

ast110 02
13. 11. 2007
0 views

ast110 02

Mura
15. 10. 2007
0 views

Mura

INECOR Amar RACHEDI
24. 10. 2007
0 views

INECOR Amar RACHEDI

Intro RED Presentation
24. 10. 2007
0 views

Intro RED Presentation

MarseilleImprimable
24. 10. 2007
0 views

MarseilleImprimable

EOT Presentation
02. 11. 2007
0 views

EOT Presentation

OM 2005 11
16. 11. 2007
0 views

OM 2005 11

csa2070 Formal slides
16. 11. 2007
0 views

csa2070 Formal slides

AdCooperate
11. 10. 2007
0 views

AdCooperate

CAPTIC2003 SV
23. 10. 2007
0 views

CAPTIC2003 SV

HPS PDS Yu 7 15 2007
01. 01. 2008
0 views

HPS PDS Yu 7 15 2007

69A Job Safety Analysis Bayne
07. 01. 2008
0 views

69A Job Safety Analysis Bayne

Public Procurement Oct04 Notes
07. 01. 2008
0 views

Public Procurement Oct04 Notes

IST444Genomicsequenc ing
16. 10. 2007
0 views

IST444Genomicsequenc ing

informesept2006
22. 10. 2007
0 views

informesept2006

FunDgnCaseStudies2005
04. 10. 2007
0 views

FunDgnCaseStudies2005

SLP PP
22. 10. 2007
0 views

SLP PP

BinghamEtalWAFINAL
04. 12. 2007
0 views

BinghamEtalWAFINAL

ecoI 5
15. 10. 2007
0 views

ecoI 5

LIDAR Leblanc
19. 10. 2007
0 views

LIDAR Leblanc

orlando opening
29. 10. 2007
0 views

orlando opening

limestone
06. 12. 2007
0 views

limestone

212w
05. 10. 2007
0 views

212w

FPBASPSreport2006
04. 10. 2007
0 views

FPBASPSreport2006

PowerIndTrucksslides
27. 02. 2008
0 views

PowerIndTrucksslides

The Six Nutrients
04. 03. 2008
0 views

The Six Nutrients

fall trash
29. 02. 2008
0 views

fall trash

icfa korea may05
13. 03. 2008
0 views

icfa korea may05

traveling
03. 04. 2008
0 views

traveling

economic cycle
08. 04. 2008
0 views

economic cycle

LAH FADR 2007 01
21. 10. 2007
0 views

LAH FADR 2007 01

retrospective10year
09. 04. 2008
0 views

retrospective10year

telemonitor full
17. 04. 2008
0 views

telemonitor full

rules
22. 04. 2008
0 views

rules

History 101
23. 10. 2007
0 views

History 101

Agrofuels DrivingClimateChange
07. 04. 2008
0 views

Agrofuels DrivingClimateChange

cdc intervention
31. 10. 2007
0 views

cdc intervention

proj 05
28. 02. 2008
0 views

proj 05

appascom
01. 10. 2007
0 views

appascom

Ross7eCh11
16. 04. 2008
0 views

Ross7eCh11

Sato pres 06
19. 02. 2008
0 views

Sato pres 06

cvamia 2004
20. 02. 2008
0 views

cvamia 2004

QDS
20. 11. 2007
0 views

QDS

poster aises
26. 11. 2007
0 views

poster aises

CM1 NY Swipe Card presentation
28. 09. 2007
0 views

CM1 NY Swipe Card presentation

mississauga
05. 10. 2007
0 views

mississauga

RuralDevSeminar
18. 10. 2007
0 views

RuralDevSeminar

slides prog 65
30. 10. 2007
0 views

slides prog 65

SachsFelix
26. 02. 2008
0 views

SachsFelix

PSC300Week7Tue
23. 12. 2007
0 views

PSC300Week7Tue

Claus xpforedrag
06. 11. 2007
0 views

Claus xpforedrag

pre as18jan48
25. 03. 2008
0 views

pre as18jan48

RA2 conclusions 2
14. 02. 2008
0 views

RA2 conclusions 2