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

 
Mass Diameter Length
Substance (g) (cm) (cm)
Aluminum 
51.5 
2.52 
3.75
Copper 
56.3 
1.23 
5.06
Brass 
94.4 
1.54 
5.69
Tin 
69.1 
1.75 
3.74
Iron 
216.1 1.89 9.77
 62. The distance from the Sun to the nearest star is about 
4 3 10
16
m. The Milky Way galaxy (Fig. P1.62) is roughly 
f
Figure P1.59 
Problems 59 and 60.
M
AMT
S
Q/C
Figure P1.62 
The Milky Way galaxy.
Ri
ch
ar
d P
ay
ne/
N
AS
A

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20
chapter 
1
physics and Measurement
Challenge Problems
 72. 
A woman stands at a horizontal distance x from a 
mountain and measures the angle of elevation of the 
mountaintop above the horizontal as u. After walking 
a distance d closer to the mountain on level ground, 
she finds the angle to be f. Find a general equation 
for the height y of the mountain in terms of d, f, and u, 
neglecting the height of her eyes above the ground.
 73. 
You stand in a flat meadow and observe two cows 
(Fig. P1.73). Cow A is due north of you and 15.0 m from 
your position. Cow B is 25.0 m from your position. From 
your point of view, the angle between cow A and cow 
B is 20.0°, with cow B appearing to the right of cow A.
(a) How far apart are cow A and cow B? (b) Consider 
the view seen by cow A. According to this cow, what 
is the angle between you and cow B? (c) Consider 
the view seen by cow B. According to this cow, what 
is the angle between you and cow A? Hint: What does 
the situation look like to a hummingbird hovering 
above the meadow? (d) Two stars in the sky appear to 
be 20.0° apart. Star A is 15.0 ly from the Earth, and 
star B, appearing to the right of star A, is 25.0 ly from 
the Earth. To an inhabitant of a planet orbiting star 
A, what is the angle in the sky between star B and our 
Sun?
Cow A
Cow B