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

Figure P1.73 
Your view of two cows in 
a meadow. Cow A is due north of you. You 
must rotate your eyes through an angle of 
20.0° to look from cow A to cow B.
S
is the volume of gas in millions of cubic feet and t is the 
time in months. Express this equation in units of cubic 
feet and seconds. Assume a month is 30.0 days.
 70. 
A woman wishing to know the height of a mountain 
measures the angle of elevation of the mountaintop as 
12.0°. After walking 1.00 km closer to the mountain on 
level ground, she finds the angle to be 14.0°. (a) Draw 
a picture of the problem, neglecting the height of the 
woman’s eyes above the ground. Hint: Use two tri-
angles. (b) Using the symbol y to represent the moun-
tain height and the symbol x to represent the woman’s 
original distance from the mountain, label the picture. 
(c) Using the labeled picture, write two trigonometric 
equations relating the two selected variables. (d) Find 
the height y.
 71. 
A child loves to watch as you fill a transparent plastic 
bottle with shampoo (Fig P1.71). Every horizontal cross 
section of the bottle is circular, but the diameters of 
the circles have different values. You pour the brightly 
colored shampoo into the bottle at a constant rate of 
16.5 cm
3
/s. At what rate is its level in the bottle rising
(a) at a point where the diameter of the bottle is 6.30 cm
and (b) at a point where the diameter is 1.35 cm?
GP
AMT
6.30 cm
1.35 cm
Figure P1.71