8
Prob. 2.1
(a) 22 6050R
(b) 22 180220R
————————————————————
Prob. 2.3
(a) Fx = +600cos30 = +520 lb
Fy = 600sin30 = 300 lb
————————————————————
Prob. 2.4
lb236)425(
13
2
lb 354)425(
13
3
(a)
y
x
F
F
————————————————————
Prob. 2.5
Px = +320cos20 = +301 lb
Py = 320sin20 = 109.4 lb
(b) Px = +640cos30 = +554 lb
Prob. 2.6
130.03.1
22
F
R = 175/(cos45 ) = 247 lb
x = tan-1(175/175) = 45
————————————————————
Fx = +300sin42 = +201 lb
Fy = 300cos42 = 223 lb
————————————————————
Prob. 2.13
(a) Fy = 650cos20 = 611 lb
Fx = 650sin20 = +222 lb
(b) Px = 120cos75 = +31.1 kN
Py = 120sin75 = 115.9 kN
9
2-2
Prob. 2.15
(a)
Fy = 800cos30 = 693 lb
lb 90)150(
5
3
F
x
————————————————————
Prob. 2.16
————————————————————
Prob. 2.17
(a) Py = 80cos20
= 75.2 k
Px = 80sin20
= 27.4 k
(b) Px = 60sin30 = 30.0 kN
Py = 60cos30 = +52.0 kN
Prob. 2.20
————————————————————
Prob. 2.21
W = weight of the skiers
W = 38(175) = 6650 lb
T = Wx = 6650sin17
= 1944 lb
Hypotenuse of slope triangle = 1
2
s
By similar triangles:
684.1
15
1
66.7
12
s
s
Resultant:
N90.12)66.7(684.1
1684.1
1
1
x
y
F
F
F
10
2-3
Prob. 2.24
(a)
lb 361200300 22
P
(d)
lb 524460250 22
P
x = tan-1(460/250) = 61.5
————————————————————
Prob. 2.25
————————————————————
Prob. 2.26
kN 3.1561.44150
22
R
————————————————————
Prob. 2.27
Prob. 2.28
For the 2-kip loads:
Prob. 2.29
6-lb force:
Fy = 6 cos19.66 = 5.65 lb
Fx = 6 sin19.66 = 2.02 lb
9-lb force:
11