Chapter 2 - Energy

Question 1

Which of the following is not a type of kinetic energy?

a. stored mechanical energy
b. motion of objects
c. radiant energy
d. electrical energy
e. thermal energy

Answer 1

a. stored mechanical energy

Question 2

Which of the following most accurately describes the earth’s energy cycle?

a. little energy is received from the sun, and instead the surface is warmed through terrestrial energy sources
b. energy is received from the sun, and all of it is absorbed, degraded and eventually reflected back to space
c. energy is received from the sun, and all of it is eventually reflected back to space
d. energy is received from the sun, some if reflected back to space, and some is absorbed, degraded and eventually reradiated back to space

Answer 2

d . energy is received from the sun, some if reflected back to space, and some is absorbed, degraded and eventually reradiated back to space

Question 3

Which of the following potential energy sources is the source of the sun’s energy?

a. gravitational energy
b. chemical energy
c. nuclear energy
d. stored mechanical energy

Answer 3

c. nuclear energy

Question 4

Shortwave radiation energy from the sun powers all of the following, except:

a. tides
b. waves
c. winds
d. rainfall
e. ocean currents

Answer 4

a. tides

Question 5

Which of the following statements most accurately describes the causes of tides on earth?

a. the tides are simply caused by the moons gravity pulling in one direction
b. the tides are simply caused by the sun’s gravity pulling in one direction
c. the source of energy for the tides is the influence of gravity on the earth’s rotation
d. the source of energy for the tides is gravity itself

Answer 5

c. the source of energy for the tides is the influence of gravity on the earth’s rotation

Question 6

Which of the following sources of energy is drawn from the earths own internal heat source?

a. nuclear energy
b. tidal energy
c. fossil fuels
d. solar energy
e. geothermal energy

Answer 6

e. geothermal energy

Question 7

The energy stored in a compressed spring is a type of stored mechanical energy.

True or False

Answer 7

True

Question 8

The ocean’s tides are primarily caused by changes in the Sun’s gravitational field

True or False

Answer 8

False

Question 9

Which of the following statements about the earth’s energy cycle is true?

a. incoming solar radiation, reflected solar radiation and the terrestrial energy sources equal emitted infrared radiation
b. incoming solar radiation and emitted infrared radiation equal reflected solar radiation and terrestrial energy sources
c. incoming solar radiation and reflected solar radiation equal the terrestrial energy sources and emitted infrared radiation
d. incoming solar radiation and the terrestrial energy sources equal reflected solar radiation and emitted infrared radiation

Answer 9

d. incoming solar radiation and the terrestrial energy sources equal reflected solar radiation and emitted infrared radiation

Question 10

Comparing the spectrum of radiation received from the sun to the spectrum emitted by the earth, which of the following statements is most true?

a. the peak wavelength emitted by the earth is higher than the peak for the sun

b/ the peak wavelength emitted by the earth is lower than the peak for the sun

c. some of the earth’s radiation is absorbed by the atmosphere, but this is not true for the sun.
d. some of the suns radiation is absorbed by the atmosphere, but this is not true for the earth.

Answer 10

a. the peak wavelength emitted by the earth is higher than the peak for the sun

Question 11

The sun alone could supply all the energy necessary for human activities into the foreseeable future

True or False

Answer 11

True

Question 12

The luminosity of the sun is constant

True or False

Answer 12

False

Question 13

Before humans began to burn fossil fuels, there was no greenhouse effect in the earth’s atmosphere

True or False

Answer 13

False

Question 14

Inside the earth, the geothermal gradient is greatest (largest change in temperature with a change in depth) in areas of:

a. radiation
b. convection
c. conduction
d. none of the choices

Answer 14

c. conduction

Question 15

In most places on the earth, how many oceanic tides are there per day (i.e. number of high tides)?

a. 1
b. 2
c. 3
d. 4

Answer 15

b. 2

Question 16

A proposed invention that would create an infinite amount of energy without any inputs would violate:

a. the second law of thermodynamics
b. the first law of thermodynamics
c. the third law of thermodynamics
d. the law of gravity

Answer 16

b. the first law of thermodynamics

Question 17

The sun will run out of the hydrogen fuel to burn in about:

a. a million years
b. a thousand years
c. a billion years
d. 4-5 billion years

Answer 17

d. 4-5 billion years

Question 18

Which layer of the sun is responsible for emitting the visible light that reaches earth?

a. chromosphere
b. corona
c. photosphere
d. core
e. convective layer

Answer 18

c. photosphere

Question 19

When plants perform photosynthesis, new energy is created

True or False

Answer 19

False

Question 20

The second law of thermodynamics constraints the efficiency of energy conversions by human activities

True or False

Answer 20

True

Question 21

What is energy?

Answer 21

the capacity to do work, to move matter, to make things happen.

Question 22

What is work?

Answer 22

the addition or subtraction to the internal energy of the system

Question 23

What is potential energy?

Answer 23

The energy stored in a system

Question 24

TYPES OF POTENTIAL ENERGY - Chemical Energy

Answer 24

the energy that holds the molecules and compounds of our world together; to change a molecule or compound energy must be added to do so or released as a consequence

Question 25

TYPES OF POTENTIAL ENERGY - Nuclear Energy

Answer 25

the energy that holds atomic nuclei together and is released when a heavy atom is split, or when two light atomic nuclei are fused to make a heavier nucleus

Question 26

TYPES OF POTENTIAL ENERGY - Stored Mechanical Energy

Answer 26

such as the energy that resides in a compressed spring or a tree sapling bent over in the wind

Question 27

TYPES OF POTENTIAL ENERGY - Gravitational Energy

Answer 27

energy of position; the energy that resides, for example, in a ball poised at the top of a steep hill, or in water at the top of a waterfall; the energy that arises from the gravitational force between two objects, such as the moon and earth.

Question 28

What is kinetic energy?

Answer 28

energy that is expressed in the movement of electrons, atoms, molecules, materials, and objects

Question 29

TYPES OF KINETIC ENERGY - radiant energy

Answer 29

or electromagnetic radiation, which travels in waveform photons of light, of which visible light is one example.

Question 30

TYPES OF KINETIC ENERGY - electrical energy

Answer 30

the movement of electrons or other charged particles, of which lightning and the aurora borealis are two natural examples

Question 31

TYPES OF KINETIC ENERGY - thermal energy

Answer 31

or heat, the vibrational movements of atoms and molecules

Question 32

TYPES OF KINETIC ENERGY - sound energy

Answer 32

results when an object is caused to vibrate; specifically, the alternating compression and expansion of a material as energy passes through it in the form of sound

Question 33

TYPES OF KINETIC ENERGY - motion energy

Answer 33

motion of objects, as in moving water or wind, or a rolling stone

Question 34

Fundamental Laws of Thermodynamics

Answer 34

The transfer of energy from one form to another and one body to another is subject to a set of natural laws known as the laws of thermodynamics

Question 35

First Law: Conservation and Transformation

Answer 35

* conservation of energy * in a system of constant mass the energy involved in any physical or chemical change is neither created nor destroyed by merely changed from one form to another

Question 36

CONCEPT IN ACTION - FIRST LAW OF THERMODYNAMICS - REVIEW the idea outlined in the first law of thermodynamics that energy can change from one form to another is a very common occurrence in earth system processes. example: a growing wheat plant uses sunlight to make carbohydrates, a form of stored chemical energy, via the process of photosynthesis. when we eat the wheat, digestion transforms the chemical energy from the plant tissues into a source of energy that is used by our bodies allowing us to walk, run, breathe. in short, the energy is transformed again into the energy of motion.

Question 37

Second Law: Efficiency and Entropy

Answer 37

* energy always changes from a more useful, more concentrated form to a less useful, less concentrated form. * an important consequence of the second law is that energy cannot be recycled to its original state of usefulness * complete recycling is impossible because whenever work is done some energy is inevitably converted to heat

Question 38

what is degradation?

Answer 38

the transformation of energy into a form that is less useful, or less available for work

Question 39

what is entrophy?

Answer 39

a measure of disorganization. equilibrium. said of the state of a system that is in balance - the more ordered energy is, the more available it is to do useful work; this happens in a system when entropy is at a minimum. * entrophy is a measure of how much of the energy of a system has been irretrievably transformed, into a disorder, dispersed, in-usable form. * the universe tends toward a state of increasing entrophy * examples: clocks run down, dead organisms decay, ice melts and mountains crumble.

Question 40

What is gradient?

Answer 40

a gradient is like a slope, but not necessarily a topographical slope; it could be a temperature pressure, a chemical slope. example: there is a very steep temperature gradient between a frozen chunk of ice and the surrounding warm air of the room. The steepness of gradients is crucial and has an impact on the amount of work and the vigor of that work that can be extracted from the system.

Question 41

Third Law: Absolute zero

Answer 41

postulated the existence of the state of absolute zero temperature

Question 42

what is temperature?

Answer 42

a measure of heat, the vibrational movement of particles. in relation to absolute zero: in a state of absolute zero temperature, all of the microscopic molecular motion on which we based our definition of heat would cease.

Question 43

what is kelvin temperature scale?

Answer 43

an absolute temperature scale because it is defined on the basis of a fundamental thermodynamic constant, the point at which entrophy is equal to zero. in relation to absolute zero: absolute zero provides the foundation point for the kelvin temperature scale.

Question 44

Other temperature scales - Review * celsius and fahrenheit scales are relative scales because they use an arbitrarily chosen reference point to define their zero. * while the kevlin and celsius scales have the same incremental scale, their state of 0 degrees is different. * kevlin uses absolute 0 or zero entrophy * celsius used the freezing point of water

Question 45

What is the main external energy source coming into earth?

Answer 45

the sun

Question 46

What is the sun?

Answer 46

the sun is a star - an enormous ball of ionized gas, or plasma that radiates heat as a result of thermonuclear reactions in its core. * the term nuclear indicates the involvement of atomic nuclei, the dense, positively charged cores of atoms.

Question 47

What is fusion (of nuclei)?

Answer 47

the merging of the nuclei of lightweight chemical elements, particularly hydrogen, to form heavier elements such as helium and carbon. * fusion only happens at exceedingly high temperatures

Question 48

What is luminosity?

Answer 48

the amount of energy (or light) radiated into space per unit of time * 4.5 x 10^6 metric tons of hydrogen are converted to helium every second, this explains luminosity being so enormous. * the sun will eventually run out of hydrogen fuel, but it will take 4.5 billion years.

Question 49

How does the earth get energy from the sun?

Answer 49

* the energy released by the fusion reactions in the sun is in the form of gamma rays, which are extremely short, high energy electromagnetic waves. * gamma rays are responsible for the energy that reaches earth * radiation is the process in which energy in the electromagnetic spectrum is transferred from a radiating or emitting body through a surrounding liquid, gas, or vacuum. radiation is how thermal energy reaches earth from the sun.

Question 50

What does the sun consist of?

Answer 50

_The sun consists of 6 concentric layers_ * the corona and chromosphere can only be clearly seen during a solar eclipse when the moon blocks the light coming from the photosphere * there are 4 inner regions that make up the sphere we see and 2 gaseous outer layers that we cannot see 1. **core** - the site of all the nuclear fusion reactions 2. **radiative layer** - also very hot but not hot enough for fusion to occur 3. **convective layer** - across this layer energy moves 4. **photosphere** - the visible layer of the sun, an intensely turbulent zone that emits the light and reaches earth. 5. **chromosphere** - a low-density layer of very hot has 6. **corona** - a zone of even lower density gas

Question 51

What is conduction?

Answer 51

the process by which heat moves directly from one object to an adjacent object to which it is in contact

Question 52

What is convection?

Answer 52

a mechanism of heat transfer in which heat content is physically carried from one location to another

Question 53

What is radiation?

Answer 53

the process in which energy in the electromagnetic spectrum is transferred from a radiating or emitting body through a surrounding gas, liquid, or vacuum

Question 54

CONCEPT IN ACTION - CONVECTION, CONDUCTION, RADIATION - REVIEW * heat is transferred from the hot stove element directly to the bottom of the pot via conduction * as the water inside the pot warms, it rises; heat is thus transferred from the bottom of the pot to the top by convection. * at the top surface, the warm water loses heat to the overlying air via conduction * the warmed air over the pot then rises, transferring heat upward into the atmosphere via convection * warmth lost from all parts of the pot to the surrounding atmosphere also will travel through the air through the process of radiation

Question 55

... more on conduction, convection, and radiation * conduction is an important process for heat to transfer in the earth system. Particularly for heat to transfer from the interior of the earth through the lithosphere to the surface. * conduction works best with materials that have high thermal conductivity such as metals * conduction that causes heat to transfer from the earth's core, though its mantle, to the base of the lithosphere, is the driving force behind plate tectonics * another example of convection is the upwards circular motion fo air which is the basis for most of earth's weather formation processes

Question 56

What absorbs most of the harmful radiation that makes it way to earth?

Answer 56

the stratosphere

Question 57

What is another way that energy comes into earth's systems?

Answer 57

the influence of gravity on earth's rotation

Question 58

Internal Energy Sources - Review In addition to the energy from the sun and tidal forces, there are sources of energy into the earth system that come from within the planet itself.

Question 59

What is geothermal gradient?

Answer 59

the increase in temperature as you go deeper towards the earths core

Question 60

Internal Energy Sources - Review * The second law of thermodynamics always flows down gradient from a warmer place to a cooler one; we deduce that heat energy must be flowing outward from the hot interior of the earth outwards. * It is calculated that the earth's core is 5000 degrees celsius, almost as hot as the surface of the sun. * heat energy that flows out through the solid rocks of earths outer most layer does so by conduction * volcanoes obviously involve the movement of hot material from inside the planet to the surface. therefore we conclude that at least some heat energy reaches earth's surface by convection * the outermost 100 km (lithosphere) is a cold, brittle, layer of rock that overlies the much hotter, more malleable rocks of the interior. * heat reaches the bottom of the lithosphere primarily by convection, and it passes through the lithosphere primarily by conduction

Question 61

Sources of terrestrial energy - Review We know the earth is nowhere near massive or dense enough to undergo nuclear reactions like the sun - it turns out that a number of processes and sources contribute to earths internal energy. radiogenic heat * main source of terrestrial energy * produced by the spontaneous breakdown or decay of radioactive elements such as uranium and thorium accretionary heat * internal heat leftover from the origins of earth and other planets of our solar system tidal heat * gravitational interactions of earth with the moon and sun cause body tides. internal friction from the constant distortion of the planet is translated into heat energy core formation * earths core formed as a result of the segregation of dense material (mainly iron) during a period when the planet was partially molten

Question 62

Does earth lose energy?

Answer 62

earth loses energy from the energy cycle in two main ways 1. reflection 2. degradation and reradiation

Question 63

How much solar energy does the earth lose?

Answer 63

about 40% of the incoming solar radiation is simply reflected, unchanged back into space, by the top of the atmosphere, the clouds, ocean surfaces, continents, and ice and snow.

Question 64

what is the greenhouse effect?

Answer 64

the property of the earths atmosphere by which long wavelength heat rays from the earth surface are trapped or reflected back by the earths atmosphere

Question 65

Energy & Society - Review geothermal Energy * drawn from earths own heat sources * theoritical limitless source of enery * very high temp at shallow depth is required to be technologically useful tidal energy * drawn from the kinetic energy associated with oceanic tides * needs high tides hydroelectric power * also recovered from the potential energy of water * stream water as it flows to the sea * not possible to supply world needs nuclear energy * heat energy produced during controlled splitting, or fission of radioactive isotopes

Question 66

Consider a lake in the sunlight. Which heat transfer process would govern the temperature of the water just below the surface of the lake? ## Footnote a. all of the above (below) b. convection c. conduction d. radiation e. none of the above

Answer 66

a. all of the above (below)

Question 67

The speed of short-wavelength radiation is faster than the speed of long-wavelength radiation True or False

Answer 67

False

Question 68

If the frequency of radiation decreases by a factor of 2, the wavelength: a. increases by a factor of 2 b. increases by a factor of 4 c. decreases by a factor of 2 d. decreases by a factor of 4 e. stays the same

Answer 68

a. increases by a factor of 2

Question 69

If there are active volcanoes in an area, which source of alternative energy is likely to be useful? a. wind b. Solar c. geothermal d. tidal

Answer 69

c. geothermal

Question 70

If there is a high demand for alcohol-based fuels, it is likely that the prices of food containing corn products will rise. True or False

Answer 70

True

Question 71

Which of the following is a NOT drawback of solar panels? a. The cost is high. b. The ultimate source of energy is not renewable. c. The efficiency is low. d. They only produce power under certain conditions.

Answer 71

b. The ultimate source of energy is not renewable.