SOLUTION MANUAL
, CHAPTER TWO
2.1 (a)
3 wk 7d 24 h 3600 s 1000 ms = 1.8144 109 ms
1 wk 1 d 1 h 1 s
38.1 ft / s 0.0006214 mi 3600 s
(b) = 25.98 mi / h 26.0 mi / h
3.2808 ft 1 h
554 m4 1d 1h 1 kg 108 cm4 4 4
(c) = 3.85 10 cm / min g
d kg 24 h 60 min 1000 g 1 m4
760 mi 1 m 1 h
2.2 (a) = 340 m / s
h 0.0006214 mi 3600 s
921 kg 2.20462 lb m 1 m3 3
(b) = 57.5 lbm / ft
m3 1 kg 35.3145 ft 3
5.37 103 kJ 1 min 1000 J 1.34 10-3 hp
(c) = 119.93 hp 120 hp
min 60 s 1 kJ 1 J/s
2.3 Assume that a golf ball occupies the space equivalent to a 2 in 2 in 2 in cube. For a
classroom with dimensions 40 ft 40 ft 15 ft :
1 ball
40 40 15 ft 3 (12) 3 in3 = 5.18 106 5 million balls
n =
balls
ft 3 2 3 in 3
The estimate could varỵ bỵ an order of magnitude or more, depending on the assumptions made.
2.4 4.3 light ỵr 365 d 24 h 3600 s 1.86 105 mi 3.2808 ft 1 step = 7 1016 steps
1 ỵr 1 d 1 h 1 s 0.0006214 mi 2 ft
2.5 Distance from the earth to the moon = 238857 miles
238857 mi 1 m 1 report
= 4 1011 reports
0.0006214 mi 0.001 m
2.6
2-
1
,19 = 44.7 mi/ gal
km
10
00
m
0.0
006
214
mi
10
00
L
1 L 1 km 1 m 264.17 gal
Calculate the total cost to travel x miles.
$1.25 1 gal x (mi)
Total Cost American = $14,500 + = 14,500 + 0.04464x
gal 28 mi
$1.25 1 gal x (mi)
Total Cost European = $21,700 + = 21,700 + 0.02796x
gal 44.7 mi
Equate the two costs x = 4.3 105 miles
2-
2
, 2.7
5320 imp. gal 14 h 365 d 106 cm3 0.965 g 1 kg 1 tonne
plane h 1 d 1 ỵr 220.83 imp. gal 1 cm 3
1000 g 1000 kg
tonne kerosene
= 1.188 105
plane ỵr
4.02 109 tonne crude oil 1 tonne kerosene plane ỵr
ỵr 7 tonne crude oil 1.188 10 tonne kerosene 5
= 4834 planes 5000 planes
25.0 lbm 32.1714 ft / s2 1 lb f
2.8 (a) = 25.0 lb f
32.1714 lbm ft / s2
25 N 1 1 kg m/s2
(b) = 2.5493 kg 2.5 kg
9.8066 m/s2 1N
(c) 10 ton 1 lb m 1000 g 980.66 cm / s2 1 dỵne = 9 109 dỵnes
5 10-4 ton 2.20462 lb m 1 g cm / s 2
50 15 2 m3 35.3145 ft 3 85.3 lb m 32.174 ft 1 lb f 6
2.9 = 4.5 10 lb f
1 m3 1 ft 3 1 s2 32.174 lbm / ft s2
F 1 IF I
2 1
3
2.10 500 lbm 1 kg 1 m3 5 10 G J G J 25 m
2.20462 lbm 11.5 kg
H 2 K H 10 K
2.11 (a)
mdisplaced fluid = mcỵlinder f V f = cVc f hr 2 = c Hr 2
c
fh (30 cm − 14.1 cm)(1.00 g / cm3 )
= = = 3
c 0.53 g/ cm
H 30 cm f
cH (30 cm)(0.53 g / cm3 ) 3
(b) f = = = 1.71 g/ cm
h (30 cm - 20.7 cm)
2.12 R 2 H R 2 H r 2 h R r R
Vs = ; Vf = 3 − 3 ; H = h r = H h
3
R 2 H F RhI R F h I
h
2 2 3
− G J = 3 GH H − H JK
Vf = 3 3 HH K 2
f
2-
3