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DDEVILEVIL PPHYSICSHYSICSBBADDESTADDEST C CLASSLASS ONON C CAMPUSAMPUS

TSOKOS READING ACTIVITYSection 7-1 (10 pts)

1. IB Assessment Statements for the following Topics:

8.1. Energy Degradation and Power Generation

8.1.1. State that thermal energy may be completely converted to work in a single process, but that continuous coversion of this energy into work requires a cyclical process and the transfer of some energy from the system.

8.1.2. Explain what is meant by degraded energy.

8.1.3. Construct and analyse energy flow diagrams (Sankey diagrams) and identify where the energy is degraded.

8.1.4. Outline the principal mechanisms involved in the production of electrical power.

8.2. World Energy Sources

8.2.1. Identify different world energy sources.

8.2.2. Outline and distinguish between renewable and non-renewable energy sources.

8.2.3. Define the energy density of a fuel.

8.2.4. Discuss how choice of fuel is influenced by its energy density.

8.2.5. State the relative proportions of world use of the different energy sources that are available.

8.2.6. Discuss the relative advantages and disadvantages of various energy sources.

8.3. Fossil Fuel Power Production

8.3.1. Outline the historical and geographical reasons for the widespread use of fossil fuels.

8.3.2. Discuss the energy density of fossil fuels with respect to the demands of power stations.

8.3.3. Discuss the relative advantages and disadvantages associated with the transportation and storage of fossil fuels.

8.3.4. State the overall efficiency of power stations fuelled by different fossil fuels.

8.3.5. Describe the environmental problems associated with the recovery of fossil fuels and their use in power stations.

8.4. Non-Fossil Fuel Power Production

8.4.1. Describe how neutrons produced in a fission reaction may be used to initiate further fission reactions (chain reaction).

8.4.2. Distinguish between controlled nuclear fission (power production) and uncontrolled nuclear fission (nuclear weapons).

8.2.3. Describe what is meant by fuel enrichment.

8.4.4. Describe the main energy transformations that take place in a nuclear power station.

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8.4.5. Discuss the role of the moderator and the control rods in the production of controlled fission in a thermal fission reactor.

8.4.6. Discuss the role of the heat exchanger in a fission reactor.

8.4.7. Describe how neutron capture by a nucleus of uranium-238 ( ) results in the production of a

nucleus of plutonium -239 ( ).

8.4.8. Describe the importance of plutonium -239 ( ) as a nuclear fuel.

8.4.9. Discuss safety issues and risks associated with the production of nuclear power.

8.4.10. Outline the problems associated with producing nuclear power using nuclear fusion.

8.4.11. Solve problems on the production of nuclear power.

2. Objectives for Tsokos Lesson 7-1:

a. Explain the meaning of the term energy degradation.

b. Understand that, in the cyclic operation of an engine, not all the available thermal energy can be transformed to mechanical work.

c. Outline how electricity is produced.

d. Understand the difference between renewable and non-renewable forms of energy.

e. State the meaning of the term energy density.

f. Understand how energy is produced by nuclear fuels.

g. Describe the function of the main elements of a nuclear reactor.

h. Appreciate the problems with nuclear fission.

i. Understand the basics of solar, wind, hydroelectric, and wave power.

j. State the meaning of the term solar constant.

k. Discuss the relative advantages and disadvantages of various energy sources.

3. Read section 7-1 in your textbook.

4. Answer the following questions:

a. What is meant by “energy degradation”?

b. In a heat engine, thermal energy is applied to a gas, the gas expands and performs work. What must

then be done to complete the cycle before it can be repeated?

c. How is thermal energy lost in this cycle?

d. In a particular engine, 1000J of energy are expended to do 350J of work. What is the efficiency of

that engine?

e. What is the predominate method for producing electricity


f. Electrical generators convert mechanical energy into electrical energy. Name five sources of

mechanical energy used to produce electricity:

i.

ii.

iii.

iv.

v.

g. Name one method of electrical energy production that does not involve mechanical energy.

h. How much energy and power does the average person in a developed country use per day?

i. How does this compare to the average person in the United States?

Below is an electrical bill for a residence with two adults and a dog. However, the period covers the holidays when the kids come home from college and you have the Christmas lights going, but that really isn’t important. This is only for the residence and does not include energy consumed at their place of work or in transportation. Also remember that this is December in Florida when there is very little air conditioning or heating needed. In summer, power consumption is nearly double this amount. Questions j through m pertain to this bill.

j. Notice that the power company charges fees based on kilowatt-hours (kWh). How many joules are

there in one kWh?

k. What was their power consumption per day per person (2 adults, 3 college students who think they

are adults that don't have to pay power bills) in kW?

l. What was their power consumption per day per person in MJ?


m. What was the total cost (energy and fuel) per person per day for electricity?

n. What are the two large classes of energy sources?

o. Explain what a non-renewable energy source is and give examples.

p. Explain what a renewable energy source is and give examples.

q. According to Table 1.1, what percentage of total energy production is renewable?

r. What is “energy density”?

s. How many times greater is the energy density of U-235 than that of gasoline?

t. How many times greater is the energy density of gasoline than that of water?

u. The low energy density of water seems to make it a poor choice for energy production. What are

some points in its favor?

v. What two things are required to decompose buried plant and animal matter?

w. Any ideas as to why we can’t just ‘manufacture’ gasoline?

x. What is the sequence of energy transitions to go from fossil fuels to electricity?

y. About how efficient are internal combustion engines (and this is considered good)?


4-Cycle Internal Combustion Engine (like your car engine)

z. What are the advantages to using fossil fuels?

i.

ii.

iii.

iv.

aa. What are the disadvantages to using fossil fuels?

i.

ii.

iii.

bb. What infrastructure (transportation, storage and distribution) considerations are associated with

fossil fuels?

cc. What is the typical type of reaction and fuel used in most nuclear power plants?

dd. What is the reaction equation for the induced fission of U-235?


ee. When a reaction is self-sustaining it is called a

ff. What must be present for the released neutron to react with other U-235 atoms and what is the name

for this?

gg. The neutrons released in the fission process have an extremely high kinetic energy. Why is this a

problem and what is used to solve the problem?

hh. Why must the neutrons available for capture by the U-235 (i.e. the reaction rate) be controlled?

ii. How are the number of available neutrons controlled?

jj. “Nuclear energy” is really the kinetic energy of released neutrons (and gamma ray photons). How is

nuclear energy translated into electrical energy (in the case of a power plant) or mechanical energy

(to power a submarine or aircraft carrier)?

kk. How is plutonium produced and what is it used for?

ll. What is the main problem with the spent fuel from a nuclear reactor and the products of the

reactions?

mm.Is there a danger that a nuclear reactor can explode like a nuclear weapon? If no (and of course the

answer is no or else I wouldn’t be adding this part of the question so the first part was really stupid,

but I digress) then what type of explosion could occur in a nuclear reactor and why is it dangerous?


nn. Barring an accident, why is nuclear power good for the environment?

oo. What gas does uranium produce and why is it dangerous?

pp. What are the advantages to using nuclear energy from fission?

i.

ii.

iii.

qq. What are the disadvantages to using nuclear energy from fission?

i.

ii.

iii.

iv.

rr. Give the equation for a typical nuclear fusion reaction.

ss. The problem in this reaction is the energy required to overcome the repulsion of the positively

charged deuterium ( ) and tritium ( ) atoms. What is the current means of doing this?

tt. What is the problem with the resulting plasma?

uu. What method for containing the plasma is currently being explored?

vv. What are the advantages to using nuclear energy from fusion?

i.

ii.

iii.

ww. What are the disadvantages to using nuclear energy from fusion?

i.

ii.

iii.

xx. What is the energy output rate of the sun?

yy. What is the average intensity of sunlight on the surface of the earth over a 24-hr time period?


zz. What are ‘active solar devices’?

aaa. What does a photovoltaic cell do?

bbb. Is production of energy the same from photovoltaic cells the same as creating electric currents

from the photoelectric effect? (and don’t get them confused!)

ccc. Then what’s the difference?

ddd. What are the advantages of solar energy?

i.

ii.

iii.

eee. What are the disadvantages of solar energy?

i.

ii.

iii.

iv.

v.

fff. What is meant by the ‘solar constant’ and what is its value on the surface of the earth?

ggg. What is ‘daily insolation’ (NOTE: this has nothing to do with Zen or anything discussed in Mrs.

Jamison’s class)

hhh. What two factors lead to lower daily insolation values for northern latitudes in the winter time

iii. Hydropower is

jjj. What is the mechanical device used to convert the potential/kinetic energy of water into

mechanical energy (not to be confused with the headgear of some members of the Hindu faith)?


kkk. Write four equations for the power supplied by falling water (use for the last one)

lll. One method of producing hydroelectric power is to pump water into a reservoir and then release it

through turbines. Why would you ever want to use this method if it takes more energy to fill the

reservoir than can be obtained when draining it?

mmm. What are the advantages of hydroelectric power (cut and paste from solar power)?

i.

ii.

iii.

nnn. What are the disadvantages of hydroelectric power?

i.

ii.

iii.

iv.

ooo. Give the equation given for the amount of power that can be extracted from wind and also give

representative values for Cp.

ppp. What are the advantages of wind power?

i.

ii.

iii.

iv.

qqq. What are the disadvantages of wind power?

i.

ii.

iii.

iv.

v.

vi.


rrr. Give the equation given for the power per unit length of a sea wave’s wavefront (consider

dispersive effects to be negligible).

sss. What does OWC stand for?

ttt. What are the advantages of wave power?

i.

ii.

iii.

iv.

uuu. What are the disadvantages of wind power?

i.

ii.

iii.

iv.

v.

vi.

vii.

5. Answers may be typed or neatly printed. Drawings may be freehand, but try to make use of the ‘Shapes’ or ‘Insert Clipart” functions of MS Word. If you submit this assignment electronically, the filename must be in the following format, “LastnameFirstinitialPerXReadActX-X”.


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