Instructor’s Manual For The Physical Universe Eighteenth Edition Konrad Krauskopf Arthur Beiser Elizabeth Shay Carter

Answers to Even-Numbered
Exercises
CHAPTER ONE
Exercises:
2. The reliance of the scientific method on
experiment and observation.
4. Because a model isolates the most important
features of a complex phenomenon, it
may permit scientists to determine the
fundamental origin of the phenomenon
with out being confused by secondary
details.
6. A year is the time the sun takes to complete
a circuit across the sky relative to the stars.
8. If the moon is seen near a particular star on
one evening, by the next evening it will be
some distance east of that star.
10. a. A year does not correspond to a whole
number of days. In order that the seasons
do not shift around the calendar, an extra
day must be added to every fourth year
with further adjustments at longer intervals.
b. A year does not correspond to a whole
number of days. In order that the seasons
do not shift around the calendar, an extra
day must be added to every fourth year
with further adjustments at longer intervals.
12. These observations suggest that the members of the solar system all lie in or near a
plane not far from the earth’s equator and
that all move in the same direction about
the sun or, in the case of the moon, about
the earth.
14. The Copernican model, because in it the
distances from the earth, and hence the
apparent brightnesses of the other planets,
vary with time.
16. Only elliptical orbits agree with observational data.
18. a. No explanation is possible in the
ptolemaic system, in which the stars are
fixed at the same distance from the earth in
a crystal ball that revolves around a
stationary earth.
b. In the copernican system the explanation
follows from the orbital motion of the earth
relative to stars at different distances away.
20. The earth would then be more flattened at
the poles and bulge to a greater extent at
the equator.
22. Yesterday, because the length of the day
has been increasing steadily since the
earth’s formation.
24. The moon.
26.
( )( ) 291 km 0.621 mi/km 181 mi =
28.
3 4 3 1 mm 10 m so 10 10 m 10 m
and 10 m 3.28 ft/m 32.8 ft
( )( )
( )( )
− −
= = =
=
d
30.
3
3 3
( ( 20.0 m 7.00 m 2.00 m 3.28 ft/m (
9.88
)
1
)
0
(
t
) )
f
=

32.
2 m 35 s 155 s / 3600 s/h 0.0431 h;
1 mi 1.61 km, speed 1.61 km /
0.0431 h 37.4 km/h
( ) ( )
( )
( )
= =
= =
=
34.
5 5 42; 7.5 10 ; 3.0 10