Page 208 - Dynamics of Mechanical Systems

0593_C06_fm Page 189 Monday, May 6, 2002 2:28 PM

Forces and Force Systems 189

F
A H 7
F n
2 B 3 G
3m
F 6
O E
F
1 F
n 2 4m 8
n 1
C 12m D F 10
F 3
FIGURE P6.3.1 F 5 F F
A force system exerted on a box. 4 9

TABLE P6.3.1
Forces, Their Magnitudes, and Lines of Action for the Force
System of Figure P6.3.1
Force Magnitude (N) Line of Action
18 BA
F 1
25 BO
F 2
30 AO
F 3
10 CB
F 4
12 OC
F 5
26 OG
F 6
20 DH
F 7
25 EO
F 8
16 DG
F 9
24 CD
F 10
P6.3.2: See Problem 6.3.1, and (a) find the moment of the force system about points C and
H, and (b) verify Eq. (6.3.6) for these results. That is, show that:
×
M = M + CH R
C H
where R is the resultant of the force system.
P6.3.3: A cube with 2-ft sides has forces exerted upon it as shown in Figure P6.3.3. The
magnitudes and lines of action of these forces are listed in Table P6.3.3.

F
A H 2

B G
E
O F
n 6
3
F
1
C F
n 2 2 ft D 5
FIGURE P6.3.3 n
1 F 3 F 4
Forces exerted on a cube.