Answers to selected problems:
Chapter 5
5.X.12
(a)
+
1.43, -8.57, 0
,
m/s, (b)
+
0.129, -0,771, 0
,
N, (c)
+
0.129, -0.771, 0
,
N
5.X.13
(a) 193 N, (b) 82 N
5.P.14
(a) zero, (b) 3, (c) -392 N, (d) 392 N, (e) 497.4 N, (f) 306.2 N, (g) 306.2 N
5.P.15
(a) dp/dt = 0, no direction, (b) zero, (c) rope, floor, (d) (255 N) cos 40 deg ~
195.3N, (e) -195.3 N, (f) Earth, floor, rope, (g) (255 N) sin 40 deg ~ 163.9, (h) (30
kg) (9.8 N/kg) ~ 294 N, (I) 294 N - 163.9 N ~ 130 N
5.P.16
10.3 cm
5.P.17
(a) 1.5 cm, (b) stretch greatest at top, decreasing as go down, (c) about 7.7 e-7 m,
(d) stretch independent of radius, therefore independent of area
5.P.18
(a) left: 6098 N, right: 7840 N, vertical: 7840 N, (b) left: 0.049, right: 0.032,
vertical: 0.063
5.P.19
(a) zero, (b) Earth, cable, air, (c) force due to cable pointing to upper right, force
due to air pointing left, force due to Earth pointing down, (d) 9530 N, (e)
+
3609,
8820, 0
,
N, (f) -3609 N, (g)
+
-3609, 0, 0
,
N, (h) yes, the cable will likely break.
5.X.20