4. 19 Determine forces acting in each bar using the graphical approach. Assume Q = 1000 N,
= 300 and = 600. (Fig. 4.21)
F
D
1
Q
2
E
FFD
Solution
Q
FFE
Use graphical method, draw FBD of point F
Use si
MEC 260: Engineering Statics
Spring 2012 - Final Exam
11:15-1:45pm, May 9
Problem Sheet (2 sides)
Problem 1. Two forces are applied to a loop as shown.
Given that P = 2000 N and = 30:
a) Express the r
MEC 260: Engineering Statics
Spring 2012 - Final Exam
11:15-1:45pm, May 9
Problem Sheet (2 sides)
Problem 1. Two forces are applied to a loop as shown.
Given that P = 2000 N and = 30:
a) Express the r
MEC 260: Engineering Statics
Fall 2012 - Final Exam
11:15-1:45pm, December 13
Problem Sheet (2 sides)
Note: As applicable, include units in your answers for full credit
y
Problem 1. Two forces are app
MEC 260: Engineering Statics
Spring 2013 - Final Exam
11:15-1:45pm, May 14
Problem Sheet (2 sides)
Note: As applicable, include units in your answers for full credit
40 N
Problem 1. Two forces are app
2.1 A 750 lb force is acting at 30 degrees to the horizontal at point A. What are the horizontal and vertical
components of this force?
Solution
The vector of the force F may be represented as F Fx i
5. 1 A force F = 12i+21j-15k acts on the point A (4,-7,9). Calculate the moment of the force
about origin of the coordinate system.
Solution
M = rxF = (4i-7j+9k)x(12i+21j-15k) =- 84i+168j+168k
5. 3 A
Aside:
Equations of Static Equilibrium hold in degrees of freedom that do not accelerate
W
W
N=W
W
qW
a
no
l.
ce
ac
q
cc e
y
l.
x
N
Note that N W ; thisFx 0 important for the discussions to
is very
f
Force is the action of one body on another
F
Force is the action of one body on another
Note: these are vectors, equal in
magnitude, opposite in direction
F
Defining the action requires: oint of appli
Static Equilibrium
F
1
M1=r1F1
M3=r3F3
r1
r3
SFi
SMO=SriFi
r2 F
F
3
1
O
F
F
2
M2=r2F2
2
F
3
Static Equilibrium of a Rigid (Free) Body
SFi
SMO=SriFi
O
r'
A
r'SFi
SFi = 0
SMO=SriFi = 0
Static Equilibriu
Rigid Body Statics
To this point we have considered only particles
Particle: (free) body small enough to be represented by a point in space,
a
or a body loaded such that all forces are applied at a po
Hw#2
1.1
The four elements are cash flows, time of occurrence of cash
flows, interest rates, and measure of economic worth.
1.10 (a) Amount paid first four years = 900,000(0.12) = $108,000 (b)
Final p
TOEIL: Eokuglen'? 5510M 5' (End 04- chapi-cfw_fr 3)
Theory
!
"if. '9 -7 ~J -J
I R-EF AZHD~E(rix_r)
F L
i V
where i :1) 23), 0
beam 7 CHM home
A Porto; on a body;
. Thu; gure. 460v: cfw_Paan 4ha1~ M
Structural Analysis
Will be presented in 3 categorizes
1) Trusses
Have no moving parts
2) Frames
3) Machines Has moving parts
For static analysis, we dont have to worry much about the categories
becau
Rigid Body Statics
To this point we have considered only particles
Particle: a (free) body small enough to be represented by a point in space,
or a body loaded such that all forces are applied at a po
Aside:
Equations of Static Equilibrium hold in degrees of freedom that do not accelerate
W
W
N=W
W
qW
y
x
q
N
Note that N W ; this isFvery
important for the discussions to follow
x 0
Fy 0 : N W cos q
Static Equilibrium
F3
F1
M1=r1F1
SMO=SriFi
F1
M3=r3F3
r1
r3
SFi
r2 F
3
O
F2
F2
M2=r2F2
Static Equilibrium of a Rigid (Free) Body
SFi
SMO=SriFi
O
A
r'
SFi = 0
SMO=SriFi = 0
r'SFi
Static Equilibrium of
MEC 260: Engineering Statics
Statics is Fundamental
Statics provides the basis for many other courses
Basic Courses in Mechanics
Rigid Body Dynamics (MEC 262)
Mechanics of Deformable Solids (MEC 363)
Mechanics of Solids (MEC 363)
Before your 1st day in Mechanics of Solids, you will be
expected to do the following very well:
Draw correct FBDs for any system.
Write the equilibrium equations for any
Exam I: What to expect
o
o
o
o
Mostly multiple choice (2/3 of the points)
Fill in the blank (equation) and complete the FBD (1/3)
Questions to test your knowledge of
Chapters 2 through 4
Vectors in 2D
Body Forces (weight) and Distributed Loads
Beam of distributed weight
Dx1
Dx2
Dxi
e.g. uniformly distributed weight: we break up the beam into chunks of
If
equal size, they will weigh the same
amount
Structural Analysis
Will be presented in 3 categorizes
1)
2)
3)
Trusses
Have no moving parts
Frames
Machines Has moving parts
For static analysis, we dont have to worry much about the categories
becau
Midterm Course Assessment
Exam 1 was: a) Incredibly easy
b) Fair and about the right length
c) Fair but too long
d) Difficult but about the right length
e) Difficult and too long
70% of class respondi
4. 5 Determine the resultant ef the three ferees Shawn.
Till H
Sfii
2F =3-ees45+?-ees+4-e053
2F =4E4N
2F. = 3-5i1145 + T-ees 30 + 400- sin 3e
2F. =1e1ew 4. 7 Find the resultant ufthe three forces sh
4. 43 Cable GB is 25 n1 leng and the tensien in that eable is 500 N. What are the a, y, and a
eempenents ef the feree exerted by cable OB e11 perth 13?
Selaen
Espress the erce in the cable acting en