Physics for Scientists & Engineers & Modern Physics, 9th Ed

Q/C
W
Q/C
W
S
 8. The mass of a copper atom is 1.06 3 10
2
25
kg, and the 
density of copper is 8 920 kg/m
3
. (a) Determine the 
number of atoms in 1 cm
3
of copper. (b) Visualize the 
one cubic centimeter as formed by stacking up identi-
cal cubes, with one copper atom at the center of each. 
Determine the volume of each cube. (c) Find the edge 
dimension of each cube, which represents an estimate 
for the spacing between atoms.
Section 1.3 
Dimensional Analysis
9. Which of the following equations are dimensionally 
correct? (a) v
f
5 v
i
1 ax (b) y 5 (2 m) cos (kx), where 
k 5 2 m
2
1
 10. Figure P1.10 shows a frustum
of a cone. Match each of the 
expressions 
(a) p(r
1 
1
r
2
)[h
2 
1
(r
2
2 r
1
)
2
]
1/2
,
(b) 2p(r
1 
1
r
2
), and
(c) ph(r
1
2
1
r
1
r
2 
1
r
2
2
)/3 
with the quantity it describes: 
(d) the total circumference of 
the flat circular faces, (e) the 
volume, or (f) the area of the 
curved surface.
 11. Kinetic energy K (Chapter 7) has dimensions kg ? m
2
/s
2
.
It can be written in terms of the momentum p (Chap-
ter 9) and mass m as
K 5
p
2
2m
h
r
1
r
2
Figure P1.10
W
Problems
the problems found in this
chapter may be assigned 
online in Enhanced Webassign
1.
straightforward; 
2.
 
intermediate;
3.
 
challenging
1.
full solution available in the Student 
Solutions Manual/Study Guide
AMT
analysis Model tutorial available in 
Enhanced Webassign
GP
Guided problem
M
Master It tutorial available in Enhanced 
Webassign
W
Watch It video solution available in 
Enhanced Webassign
BIO
Q/C
S
L
d
a
b
Figure P1.7

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16
chapter 
1
physics and Measurement
 22. Assume it takes 7.00 min to fill a 30.0-gal gasoline tank. 
(a) Calculate the rate at which the tank is filled in gal-
lons per second. (b) Calculate the rate at which the 
tank is filled in cubic meters per second. (c) Determine 
the time interval, in hours, required to fill a 1.00-m
3
volume at the same rate. (1 U.S. gal 5 231 in.
3
)
 23. A section of land has an area of 1 square mile and 
contains 640 acres. Determine the number of square 
meters in 1 acre.
 24. A house is 50.0 ft long and 26 ft wide and has 8.0-ft-
high ceilings. What is the volume of the interior of the 
house in cubic meters and in cubic centimeters?
 25. One cubic meter (1.00 m
3
) of aluminum has a mass of 
2.70 3 10
3 
kg, and the same volume of iron has a mass 
of 7.86 3 10
3
kg. Find the radius of a solid aluminum 
sphere that will balance a solid iron sphere of radius 
2.00 cm on an equal-arm balance.
 26. 
Let r
Al
represent the density of aluminum and r
Fe
that 
of iron. Find the radius of a solid aluminum sphere 
that balances a solid iron sphere of radius r
Fe
on an 
equal-arm balance.