.RENE S.

ARCILLA
STATICS : Chapter II Presentation:
Civil & Geodetic Engineer

FORCES AND COMPONENTS

y
C Free vector of Fx
Free vector of Fy

3 km
Fy F
Fy
A B
x x
4 km
O Fx
(a)
C Fy
sin = ; Fy = Fsin
F
Fx
cos = ; Fx = Fcos
F
A 45
4 km B
F = (Fx)2 + (Fy)2
(b)

Fy
tan =
Fx

HAU CEA SY 2013 - 2014 Chapter II Forces and Components

 .RENE S. ARCILLA
STATICS : Chapter II Presentation:
Civil & Geodetic Engineer

VECTOR ORIENTATION:

Up to Left Up to Right
y y
F Fy
F
(+) Fy
x x (+) x
x
O O

Fx ( ) Fx ( + )
II I

y III IV y
Fx ( )
Fx ( + )
O x
O
x x
x
Fy Fy
() ()
F F

Down to Left Down to Right

 .RENE S. ARCILLA
STATICS : Chapter II Presentation:
Civil & Geodetic Engineer

PRACTICE PROBLEMS:
#204 Determine the X and Y components of each of the forces shown in the figure.
p18
F=390 lb Y

12
5
X
40 30

P=300 lb
T=400 lb

HAU CEA SY 2013 - 2014

 .RENE S. ARCILLA
STATICS : Chapter II Presentation:
Civil & Geodetic Engineer

PRACTICE PROBLEMS:
#205 Determine the X and Y components of each of the forces shown in the figure.
p19
Y
P=200 lb
T=722 lb

3
2 40
X

1
2
F=448 lb
 .RENE S. ARCILLA
STATICS : Chapter II Presentation:
Civil & Geodetic Engineer

PRACTICE PROBLEMS:
#206 The triangular block shown is subjected to the loads P = 1600 lb and F = 600 lb. If
p19 AB = 8 in. and BC = 6 in., resolve each load into components normal and tangential
to AC. A

P=1600 lb

C B

F=600 lb
 .RENE S. ARCILLA
STATICS : Chapter II Presentation:
Civil & Geodetic Engineer

PRACTICE PROBLEMS:
#207 Rework Prob. 206 if = 60. Given that AB = 8 in. and BC = 6 in.
p19
A

P=1600 lb

C B

F=600 lb
 .RENE S. ARCILLA
STATICS : Chapter II Presentation:
Civil & Geodetic Engineer

PRACTICE PROBLEMS:
#208 The horizontal and vertical components of several forces are: (a) Ph = 200 and
p19 Pv = 100 lb; (b) Fh = 300 lb and Fv = 200 lb; (c) Th = 50 lb and Tv = 90 lb.
Determine each force.
 .RENE S. ARCILLA
STATICS : Chapter II Presentation:
Civil & Geodetic Engineer

PRACTICE PROBLEMS:
#209 Repeat Prob. 208 if (a) Ph = 150 and Pv = 200 lb; (b) Fh = 240 lb and Fv = 360 lb;
p19 (c) Th = 500 lb and Tv = 300 lb.