Chapter 6 Questions and Answers
Page 30
1. Explain how tilt and rotation cause day and night.
As the earth revolves around the sun different amounts of radiant
energy from the sun hit the Northern and Southern hemispheres.
When the hemisphere is pointed toward the sun, it receives more
energy than the hemisphere pointing away.
B.
Explain how tilt and revolution result in variations in the lengths
of day and night.
The length of day and night vary with the angle between the circle
of illumination and the equator. When this angle is perpendicular,
there are about 12 hours of light. As the angle in darkness becomes
greater, the amount of darkness increases. As the angle becomes
acute, the amount of darkness decreases.
2. Student answers.
3. In what way are the Arctic and Antarctic Circle significant
lines of latitude with respect to day and night?
These parallels delineate regions of the earth where at least one
day and one night are 24 hours long.
Page 32
1 b) Is there a positive or negative correlation between latitude
and temperature?
Negative correlation.
c) What conclusions can you draw from the scattergraph?
As you travel away from the equator, the temperature drops.
Conversely, the lower the latitude, the higher the temperature.
d) What could account for any anomalies?
Anomalies could result from ocean currents like the North
Atlantic Drift, differences in elevation, and, to a lesser extent,
variations in surface albedo.
3. How does the fact that temperature increases as you go
toward the equator affect the way people live?
Answers will vary
4. Explain how the earth’s tilt and revolution cause the seasons.
Because the earth revolves around the sun and because it is
tilted, different parts of the earth pointing toward the sun receive
more direct solar radiation than parts that are pointing away. For
example, as the Northern Hemisphere becomes increasingly tilted
toward the sun, the angle at which the sun’s rays intersect with the
earth’s surface decreases. The sun’s rays are thus concentrated on a
smaller surface area of the earth than when the hemisphere is
pointing away from the sun.
P. 34
1 a) Does the environmental lapse rate have a positive or negative
correlation
It has a negative correlation.
b) Why does environmental lapse rate occur?
Temperature decreases with elevation for three reasons. The air
pressure is lower aloft, therefore air molecules do not hold heat as
well. You are moving away from the source of heat which is the
surface of the earth. Dust particles and humidity are greater close
to the earth. These act as an insulation to hold the heat in at lower
temperatures.
c) If you were to climb a mountain describe what would happen to
each of the following:
temperature- drops
air pressure- drops
pollution- decreases
humidity- decreases
2. How are altitude and latitude similar in the ways in which they
influence solar radiation?
As altitude and latitude increase, average temperature decreases.
3. Explain how the environmental lapse rate influences how people
live?
Answers will vary
4. a) Calculate the mean elevation and mean population for the
ten largest South American cities.
South America- Mean elevation- 893.5 m
Mean population- 5.09 million
b ) Calculate the mean elevation and population for the ten
largest Canadian cities.
Canada- Mean elevation- 255.7 m
Mean population- 1.11 million
c) What patterns do you notice?
Most South American cities are located at higher elevations
or at coastal locations, probably because the temperatures are
cooler here than in the interior lowlands.