1. Various geometric formulas are given in Appendix E.
(a) Expressing the radius of the Earth as
R = (6.37 × 106 m)(10−3 km m) = 6.37 × 103 km,
its
... [Show More] circumference is s = 2π R = 2π (6.37 × 103 km) = 4.00×104 km.
(b) The surface area of Earth is ( )A = 4π R2 = 4π 6.37 × 103 km 2 = 5.10 × 108 km2.
(c) The volume of Earth is ( )4 3 4 6.37 103 km 3 1.08 1012 km3.
3 3
V R π π
= = × = ×
2. The conversion factors are: 1 gry =1/10 line , 1 line =1/12 inch and 1 point = 1/72
inch. The factors imply that
1 gry = (1/10)(1/12)(72 points) = 0.60 point.
Thus, 1 gry2 = (0.60 point)2 = 0.36 point2, which means that 0.50 gry2= 0.18 point2 .
3. The metric prefixes (micro, pico, nano, …) are given for ready reference on the inside
front cover of the textbook (see also Table 1–2).
(a) Since 1 km = 1 × 103 m and 1 m = 1 × 106 μm,
1km = 103 m = (103 m)(106 μ m m) = 109 μm.
The given measurement is 1.0 km (two significant figures), which implies our result
should be written as 1.0 × 109 μm.
(b) We calculate the number of microns in 1 centimeter. Since 1 cm = 10−2 m,
1cm = 10−2 m = (10−2m)(106 μ m m) = 104 μm.
We conclude that the fraction of one centimeter equal to 1.0 μm is 1.0 × 10−4.
(c) Since 1 yd = (3 ft)(0.3048 m/ft) = 0.9144 m,
2 CHAPTER 1
1.0 yd = (0.91m)(106 μ m m) = 9.1 × 105 μm.
4. (a) Using the conversion factors 1 inch = 2.54 cm exactly and 6 picas = 1 inch, we
obtain
0.80 cm = (0.80 cm) 1 inch 6 picas 1.9 picas.
2.54 cm 1 inch
⎛ ⎞⎛ ⎞≈
⎜ ⎟⎜ ⎟
⎝ ⎠⎝ ⎠
(b) With 12 points = 1 pica, we have
0.80 cm = (0.80 cm) 1 inch 6 picas 12 points 23 points.
2.54 cm 1 inch 1 pica
⎛ ⎞⎛ ⎞⎛ ⎞≈
⎜ ⎟⎜ ⎟⎜ ⎟
⎝ ⎠⎝ ⎠⎝ ⎠
5. Given that 1 furlong = 201.168 m, 1 rod = 5.0292 m and 1chain = 20.117 m, we find
the relevant conversion factors to be
1.0 furlong 201.168 m (201.168 m) 1 rod 40 rods,
5.0292 m
= = =
and
1.0 furlong 201.168 m (201.168 m) 1 chain 10 chains
20.117 m
= = = .
Note the cancellation of m (meters), the unwanted unit. Using the given conversion
factors, we find
(a) the distance d in rods to be
4.0 furlongs (4.0 furlongs) 40 rods 160 rods,
1 furlong
d = = =
(b) and that distance in chains to be
4.0 furlongs (4.0 furlongs)10 chains 40 chains.
1 furlong
d = = =
6. We make use of Table 1-6.
(a) We look at the first (“cahiz”) column: 1 fanega is equivalent to what amount of cahiz?
We note from the already completed part of the table that 1 cahiz equals a dozen fanega.
Thus, 1 fanega = 1
12 cahiz, or 8.33 × 10−2 cahiz. Similarly, “1 cahiz = 48 cuartilla” (in the
already completed part) implies that 1 cuartilla = 1
48 cahiz, or 2.08 × 10−2 cahiz.
Continuing in this way, the remaining entries in the first column are 6.94 × 10−3 and
3.47×10−3 .
3
(b) In the second (“fanega”) column, we find 0.250, 8.33 × 10−2, and 4.17 × 10−2 for the
last three entries.
(c) In the third (“cuartilla”) column, we obtain 0.333 and 0.167 for the last two entries.
(d) Finally, in the fourth (“almude”) column, we get 12
= 0.500 for the last entry.
(e) Since the conversion table indicates that 1 almude is equivalent to 2 medios, our
amount of 7.00 almudes must be equal to 14.0 medios.
(f) Using the value (1 almude = 6.94 × 10−3 cahiz) found in part (a), we conclude that
7.00 almudes is equivalent to 4.86 × 10−2 cahiz.
(g) Since each decimeter is 0.1 meter, then 55.501 cubic decimeters is equal to 0.055501
m3 or 55501 cm3. Thus, 7.00 almudes = 7.00
12 fanega = 7.00
12 (55501 cm3) = 3.24 × 104 cm3.
7. We use the conversion factors found in Appendix D.
1 acre ⋅ ft = (43,560 ft2 ) ⋅ ft = 43,560 ft3
Since 2 in. = (1/6) ft, the volume of water that fell during the storm is
V = (26 km2 )(1/6 ft) = (26 km2 )(3281ft/km)2 (1/6 ft) = 4.66×107 ft3.
Thus,
V =
×
× ⋅
4 66 10 = × ⋅
4 3560 10
11 10
7
4
. 3
.
ft .
ft acre ft
acre ft.
3
3
8. From Fig. 1-4, we see that 212 S is equivalent to 258 W and 212 – 32 = 180 S is
equivalent to 216 – 60 = 156 Z. The information allows us to convert S to W or Z.
(a) In units of W, we have
50.0 S (50.0 S) 258 W 60.8 W
212 S
⎛ ⎞
= ⎜ ⎟ =
⎝ ⎠
(b) In units of Z, we have
50.0 S (50.0 S) 156 Z 43.3 Z
180 S
⎛ ⎞
= ⎜ ⎟ =
⎝ ⎠
9. The volume of ice is given by the product of the semicircular surface area and the
thickness. The area of the semicircle is A = πr2/2, where r is the radius. Therefore, the
volume is
4 CHAPTER 1
2
2
V rz π
=
where z is the ice thickness. Since there are 103 m in 1 km and 102 cm in 1 m, we have
( )
3 2
2000 km 10 m 10 cm 2000 105 cm.
1km 1m
r
⎛ ⎞ ⎛ ⎞
= ⎜ ⎟ ⎜ ⎟ = ×
⎝ ⎠ ⎝ ⎠
In these units, the thickness becomes
( )
2
3000m 3000m 10 cm 3000 102 cm
1m
z
⎛ ⎞
= = ⎜ ⎟ = ×
⎝ ⎠
which yields ( ) ( ) 2000 105 cm 2 3000 102 cm 1.9 1022 cm3.
2
V
π
= × × = ×
10. Since a change of longitude equal to 360° corresponds to a 24 hour change, then one
expects to change longitude by360° / 24 =15° before resetting one's watch by 1.0 h.
11. (a) Presuming that a French decimal day is equivalent to a regular day, then the ratio
of weeks is simply 10/7 or (to 3 significant figures) 1.43.
(b) In a regular day, there are 86400 seconds, but in the French system described in the
problem, there would be 105 seconds. The ratio is therefore 0.864.
12. A day is equivalent to 86400 seconds and a meter is equivalent to a million
micrometers, so
37 10
14 86400
31
. 6
. .
m mm
day s day
m s
b gc h
b gb g
μ
= μ
13. The time on any of these clocks is a straight-line function of that on another, with
slopes ≠ 1 and y-intercepts ≠ 0. From the data in the figure we deduce
2 594 , 33 662 .
C 7 B 7 B 40 A 5 t = t + t = t −
These are used in obtaining the following results.
(a) We find
33 ( ) 495 s
40 B B A A t′ − t = t′ − t =
when t'A − tA = 600 s. [Show Less]