PHYS 221 – Environmental Physics – Spring 2010 – Quiz 1
Question 1 (1pt) :The Principle of Energy Conservation is:
a. a possible means for extending our fossil fuel reserves
b. Inconsistent with the motion of a pendulum
c. a law of physics often violated in thermodynamics systems
d. a law of physics with no known exceptions
e. obeyed in chemical reactions but not on nuclear reactions
Question 2 (1pt): Kinetic and potential; energies are energies of____ and ____,
respectively.
a. springs and gravity
b. solids and liquids
c. position and motion
d. motion and position
e. force and power
Question 3 (1pt): One horsepower for one hour represents how many joules?
a. 44,760
d. 746
b. 2,685,600
e. 3,413
c. 33,390,960
f. None of the above
Question 4 (1pt): Coal, oil and gas represent approximately___%,___% and ___%,
respectively of the US fossil fuel energy use.
a. 27, 46, 27
d. 35, 35, 30
b. 25, 20, 55
e. 52, 38, 10
c. 90, 5, 5
Question 5 (1pt): In the Unites States the total energy consumed per year per person is
equivalent of about _____barrels of oil
a. 5.8
b. 58
c. 580
d. 5800
Question 6 (1pt): The total annual energy consumption in the United States is about
___QBtu, and this is the equivalent of about ___tons of coal per year for each person.
a. 80, 13
c. 8000, 1.4
b. 800, 130
d. 98, 13
Question 7 (1pt): For an ideal heat engine, according to Carnot:
a. Th/Tc=Qc/Qh
b. Tc/Th=Qc/Qh
c. Th/Qc=Tc/Qh
d. Tc/Qc=Qh/Th
Question 8 (1pt): For an ideal heat engine operating between thermal reservoirs at
Th=1000˚C and Tc = 110˚C, the efficiency is____
a. 10%
f. 95%
b. 29%
g. 98%
c. 70%
h. Cannot be determined from
d. 90%
information given
e. 92%
Question 9 (1pt): A typical efficiency for a coal-burning electric power plant is___
a. 1%
e. 33%
b. 2%
f. 66%
c. 5%
g. 90%
d. 25%
Question 10 (1pt): A heat engine_____
a. pumps energy “uphill”
b. is identical in function to a heat pump
c. can produce work from a temperature difference
d. can occasionally violate the principle of conservation of energy
e. is only an idea not yet achieved
Question 11 (1pt): The coefficient of performance of a good heat pump is_____
a. a negative number
b. equal to the number 1.0
c. larger for smaller temperature difference
d. smaller for smaller temperature difference
e. not a numerical quantity
f. meaningless
Question 12 (2pts): A heat engine in each cycle extracts 50,000 Btu of thermal energy
and rejects (or releases) 20,000 Btu of thermal energy
(a) How many Btu of work are done each cycle?
(b) What is the efficiency of this engine?
Question 13 (2pts): A heat engine operating between a geothermal steam source at 210˚C
and a river at 20˚C achieves an efficiency of 20%. What percentage of its theoretical
maximum efficiency is it achieving?