Practice Exam 1 - Environmental Science - page 240

E. Cite and explain at least two possible issues associated with the proposed method of pollution con-
tainment (2 points maximum):
• 1 point: Contaminants are not being removed from the water source.
• 1 point: The covered contaminants could be disturbed by natural events including flooding of the
river, shifting of the river bed, or earthquake.
• 1 point: The contaminants could be disturbed by human activities such as dredging.
• 1 point: If the sediment is disturbed, the pollution will be disturbed, reintroducing the contaminants
into the river ecosystem.
2. This question is worth a maximum of 10 points, as follows:
A. Calculate the following, showing all the steps of your calculations.
a. The number of kWh of electricity used to cool the house for the summer (2 points maximum—1
point for setup, 1 point for correct answer):
Number of Days = 30 (June) + 31 (July) + 31 (August) + 30 (September) = 122 days
kWh used = Number of Days × kWh per day = 122 days × 25 kWh per day = 3,050 kWh
b. The cost of cooling the house for the summer (2 points maximum—1 point for setup, 1 point for
correct answer):
Cost = kWh × $0.10 per kWh = $305
Make sure to include proper units in each step.
B. Identify and describe two actions the owner of the house could take to conserve electrical energy,
aside from replacing the air-conditioning unit with a more energy-efficient model (2 points maxim-
um):
• 1 point: Replace single-paned windows with double- or triple-paned windows.
• 1 point: Add or increase insulation in the walls.
• 1 point: Add or increase insulation in the ceiling.
• 1 point: Turn the thermostat up to a higher temperature and wear less clothing to stay cool.
• 1 point: Replace light bulbs with compact florescent light (CFL) bulbs or install dimmer switches.
• 1 point: Turn off lights when not in use.
• 1 point: Unplug appliances when not in use. (Some appliances plugged into the outlets still use a
little electricity.)
• 1 point: Turn down the water temperature on the water heater.
• 1 point: Buy a more energy-efficient appliance such as a refrigerator, electric stove, dishwasher,
washing machine, or electric dryer.
• 1 point: Any other reasonable energy-saving strategy.
C. The owner has been considering replacing the air-conditioning unit because it is more than 25 years
old. Discuss one environmental cost and one environmental benefit of replacing the air-conditioning
unit and one economic cost and one economic benefit of replacing the unit (4 points maximum):
• Environmental cost (1 point):
1 point: Replacing the unit requires production of a new unit, especially including mining for metals,
so it increases CO 2 emissions from mining equipment and the transport of raw materials, and con-
tributes to greenhouse-gas emissions and global climate change.