# Lab module 3: earth sun relationship

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LAB MODULE 3: EARTH SUN RELATIONSHIP

Note: Fascinate apply to the GETTING STARTED lab module to collect tips on how to set

up and maneuver through the Google Earth ( ) content of this lab.

KEY TERMS

The forthcoming is a inventory of leading opinion and concepts used in this lab module:

Analemma Equation of interval Solstice

Aphelion Equinox Sphericity

Axial equality Insolation Subbrilliant subject-matter

Axial Tilt International Limit Superscription Sun Angle

Circle of sunshine NDVI Sun-fast, Sun-slow

Coordinated Universal Interval (UTC) Perihelion Interval zones

Declination of Sun Rotation

LAB MODULE LEARNING OBJECTIVES

After successfully completing this lab module, you should be effectual to:

● Compute destructions in interval betwixt two dregs

● Recognize and inform how interval zones work

● Differentiate the fluctuates in the foe of sunshine counteract the order of a

year

● Identify and recount the debates for the periods

● Infer vegetation as an indicator for periodality

● Decipher and solve an analemma

● Calculate the Sun’s slope for a absorbed dregs and limit

● Compute the equation of interval for a absorbed dregs

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INTRODUCTION

This lab module inspects essential Earth-Sun connections. Topics apprehend interval

zones, the equation of interval, analemma, slope, solstice and equinox, the

reasons for periods, and the periodal locomotion of the subbrilliant subject-matter. Suitableness these

topics may seem different, you procure collect how they are inherently cognate.

The modules set-on-foot delay indecent initiation subject-matters, or vignettes, institute in the

accompanying Google Earth finish. These vignettes produce-disclosed basic concepts cognate to

Earth-Sun connections. Some of the vignettes accept alertnesss, videos, or short

articles that procure collect another perspective or visual sense for the subject-matter at

hand. Aftercited balbutiation each vignette and associated links, acceptance the forthcoming

questions. Fascinate music that some contents of this lab may accept a suitableness to

Expand EARTH-SUN RELATIONSHIPS, and then spdecipher the INTRODUCTION

folder. Double click Subject-matter 1: Earth-Sun Relations.

Question 1: Looking at the maps, which of the forthcoming best showcases the

uneven counteract of insolation – and effecting periodality - on planet Earth?

A. Most of the northern hemiworld is unimpeded of ice and snow year round

B. Most of the northern hemiworld is tried in ice and snow year round

C. Most of the northern hemiworld shows ice and snow advancing in the

July

D. Most of the northern hemiworld shows ice and snow retiring in July

Read Subject-matter 2: Debate for Seasons. (Note: If you are having issues guarding

automatically munificent via the webpage)

Question 2: Why does each hemiworld assent-to the selfselfcorresponding totality of spectre

from the Sun on the March and September equinoxes?

E. The subbrilliant subject-matter is aligned delay the Tropic of Cancer

F. The subbrilliant subject-matter is aligned delay the Tropic of Capricorn

G. The subbrilliant subject-matter is aligned delay the Equator

H. The subbrilliant subject-matter is aligned delay the North Pole

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Question 3: What was the deep debate for instituting type interval (time

zones)?

A. To end indistinctness in communities using their own brilliant interval

B. To aid astrologers prevent oppidan augmentation patterns

C. To reaffirm England’s world dominance

D. To valilimit the Culmination Conference of 1884

Question 4: Name 3 debates occasion-honored cultures used stone structures or

modified intrinsic formations concerning Earth-Sun or Earth-Moon connections.

A. To chart periods, produce calendars, and commend birthdays

B. To instructor eclipses, vestige deaths, demusic holidays

C. To chart periods, instructor eclipses and produce calendars

D. To commend birthdays, vestige deaths and demusic the end of days

Collapse and unrecrush the INTRODUCTION folder.

GLOBAL PERSPECTIVE

I. Coordinated Universal Interval (UTC)

The Earth is disjoined into 24 interval zones, one for each hour of the day. Earth’s 24

interval zones are almost 15° remote – a width congenial from the reckon of

degrees in a world disjoined by the reckon of hours in a day (360°/24hr =

15°/hour). Noon (12pm) befalls roughly when the Sun is at its pre-eminent subject-matter in the

sky each day. For illustration, noon in New York is three hours antecedently noon in Los

Angeles accordingly there is (approximately) a three hour destruction in when the Sun

is at its pinnacle.

Expand the GLOBAL PERSPECTIVE folder and then spdecipher and primeeded the

Universal Interval Coordinated folder.

Time zones are as fur a Sun-Earth connection as they are a anthropological construct

used to typeize interval. The Prime Culmination - which signifies 0 stations lip

and passes through Greenwich, England - is the set-on-footing applyence superscription for interval

zonation. Interval zones are not-absolute to Greenwich Balance Interval (GMT) or further

appropriately, the Coordinated Universal Interval (UTC). Examples are New York City,

USA in the wane at UTC -5 (or 5 hours aftercited UTC), or Manila, Philippines at

UTC+8 (or 8 hours onwards of UTC). In other opinion, when it is 8am in New York, it is

9pm in Manila.

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As you can see in Google Earth, interval zones do not steadyly flourish unswerving superscriptions from

pole to pole accordingly of gregarious, economic, or geographic debates. Interval zone

anomalies apprehend the forthcoming:

Time Zone Abnormity Example

Time zone extends far superior or shorter

than 15 stations.

China is one interval zone.

Time zones shifts significantly eastward

or westward.

Iceland shifts 2 interval zones to be UTC 0.

Time zone does not flourish the 1-hour

system. Instead, a specific interval-zone unit

is used.

(summer 2:30 UTC), suitableness Nepal is 5:45

UTC

Double-click São Paulo, Brazil. You command accept to pan northward to discaggravate the

interval zone dedicate nigh the Equator.

Question 5: In what UTC interval zone is this city located?

A. UTC -2

B. UTC -3

C. UTC +2

D. UTC+3

Question 6: If UTC 0 interval is 1pm, what is the type interval for this city?

A. 10 AM

B. 11 AM

C. 3 PM

D. 4 PM

Double-click Cape Town, RSA. You command accept to pan northward to discaggravate the

interval zone dedicate nigh the Equator.

Question 7: In what UTC interval zone is this city located?

A. UTC -1

B. UTC -2

C. UTC +1

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D. UTC+2

Question 8: If UTC 0 interval is 1pm, what is the type interval for this city?

A. 11 AM

B. 12 PM (NOON)

C. 2 PM

D. 3 PM

Double-click Kuala Lumpur, Malaysia. You command accept to pan northward to

discaggravate the interval zone dedicate nigh the Equator.

Question 9: Which of the forthcoming best recounts the interval zone abnormity

affecting this city and kingdom?

A. Interval zone extends far superior or shorter than 15 stations

B. Interval zone shifts significantly eastward or westward

C. Interval zone does not flourish the type 1 hour system

D. There is no interval zone for the absorbed dregs

Question 10: What is the principal debate for this interval zone abnormity?

A. Gregarious boundaries of Malaysia

B. Economic traffic for Southeast Asia

C. Railway schedules

D. International law

Question 11: In what UTC interval zone is this city located?

A. UTC-7

B. UTC-8

C. UTC +7

D. UTC +8

Question 12: If UTC 0 interval is 1pm, what is the type interval for this city?

A. 8 PM

B. 9 PM

C. 5 AM

D. 6 AM

Double-click, and primeed, Pitcairn Islands

Question 13: Which of the forthcoming best recounts the interval zone abnormity

affecting these islands?

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A. Interval zone extends far superior or shorter than 15 stations

B. Interval zone shifts significantly eastward or westward

C. Interval zone does not flourish the type 1 hour system

D. There is no interval zone for the absorbed dregs

Question 14: What is the principal debate for this interval zone abnormity?

A. Geographic dregs of the islands

B. Economic traffic for the islands

C. International law

D. Strict mental code

Question 15: In what UTC interval zone are these islands located?

A. UTC -6

B. UTC -8.5

C. UTC +6

D. UTC +8.5

Question 16: If UTC 0 interval is 1pm, what is the type interval for these

islands?

A. 4:30 PM

B. 9:30 PM

C. 4:30 AM

D. 9:30 AM

Collapse and unrecrush the Universal Interval Coordinated folder.

II. Considerableness Savings

Double-click, and primeed, Considerableness Reluctant Time

Many regions in the world accept adopted considerableness reluctant interval (DST), or the

advancing of UTC interval for a absorbed dregs. This is chiefly gentleman for North America

and Europe. As an illustration, New York, New York propels from Eastern Standard

Time (EST) to Eastern Considerableness Interval (EDT) betwixt the months of March and

November. The type interval during considerableness reluctant interval is adjusted from UTC -5

(EST) to UTC -4 (EDT).

Question 17: If it is 12 PM (noon) in Manila, Philippines (UTC +8), what is

the interval during EDT in New York (UTC -4)?

A. 12 AM

B. 4 PM

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C. 8 PM

D. 8 AM

III. International Limit Line

Double-click the International Limit Superscription folder and then recrush the IDL folder.

The International Limit Superscription (IDL) is an suppositious superscription that runs from pole to pole on

further or short the 180°E/W longitude. Noteffectual litigious to this bedroop from 50°N to

75°N and from the Equator to 50°S.

If you cantankerous the IDL traveling westwardly (from east to west), you insufficiency to add a

day to your interval. In other opinion, a Thursday becomes a Friday. If you cantankerous the

IDL traveling eastwardly (from west to east), you would aftercited a whiledraw a day. For

example, a Friday becomes a Thursday. To imagine of it another way, the Earth

“starts” the day (12:01 am) on the west face of the IDL, and accepts a ample 24 hours

for 12:01 am to gain the east face of the IDL.

Double-click and primeeded IDL North.

Question 18: Why does the IDL swerve from 180° E/W in this dregs?

A. To totality for the accelerateder orderal hurry inface the North Pole

B. The IDL is forthcoming the 180° E/W culmination – there is no deflexion in this

location

C. To flourish the bathymetry of the sea in this dregs

D. To accept the islands of Alaska in the selfselfcorresponding interval zone as the tranquillity of Alaska

Double-click and primeeded IDL South.

Question 19: Why does the IDL swerve from 180° E/W in this dregs?

A. To totality for the accelerateder orderal hurry inface the Equator

B. To flourish the bathymetry of the sea in this dregs

C. To accept the islands of Kiribati in the selfselfcorresponding interval zone.

D. To disconnected the islands countries on the west face of the IDL from the

island countries located east of 180° E/W

Collapse and unrecrush the GLOBAL PERSPECTIVE folder.

REASONS FOR SEASONS

There are five different debates for the periods – tilt (at 23.5 stations), office

(environing the Sun), order (total 24 hours), axial equality (agricultural alignment

during office environing Sun), and globosity (the Earth’s outline). These five

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reasons totality for the indecent divisions of the year - emerge, summer, autumn (fall),

and wane – frequently vestigeed by different sky patterns, temperatures

fluctuations, vegetation unpractisedess and so on. The station of these periodal fluctuate

becomes further seeming as you propel afar from the Equator (as periodality in

tropical regions is minimal).

In this individuality, we procure inspect three of the five debates for the periods – axial tilt,

revolution, and order.

I. Axial Tilt

Because of the tilt of the Earth, the totality of spectre Earth assent-tos from the Sun

is contingent on dregs and interval of year. On the equinoxes (March 20 and

September 22 or 23), the Sun is at-once counteracthead (the sub-brilliant subject-matter) and all

areas on Earth assent-to the selfselfcorresponding 12 hours of brilliant spectre (sunlight). On the

solstices (June 20 or 21 and December 21 or 22), the subbrilliant subject-matter is on the tropic

of cancer (23.5 stations North) or the tropic of capricorn (23.5 stations South),

resulting in the most illmatched disposal of brilliant spectre on Earth.

Expand and primeeded the REASONS FOR SEASONS folder. Double-click

Overvision and then decipher the passage and guard the alertness.

Question 20: What is the connection betwixt the periods and the lie

of the sub-brilliant subject-matter?

A. The sub-brilliant subject-matter is furthest north during the emerge equinox

B. The sub-brilliant subject-matter is furthest north during the autumn equinox

C. The sub-brilliant subject-matter is furthest north in summer (June) solstice

D. The sub-brilliant subject-matter is furthest north in wane (December) solstice

Question 21: Explain how Earth’s periods would be if the Earth did not tilt

on its axis.

A. Annually, there would be further than indecent periods

B. Annually, there would be no further periods

C. Annually, there would be one dry period and one wet period

D. Annually, there would one “hot” period on Earth

II. Revolution

It accepts 365.24 days for the Earth to thorough one office environing the Sun. And

although the Earth’s deflection is suggestive , the departure in interval betwixt the Earth’s

deflection nighest to the Sum (perihelion) or ultimate from the Sun (alphelion) is not

great plenty to totality for the periods.

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Question 22: Assume the Earth was tilted and agitated, but did not revolve

environing the Sun. How would this wave the dregs of sub-brilliant subject-matter counteract

a absorbed year?

A. The sub-brilliant subject-matter would not propel

B. The sub-brilliant subject-matter would propel daily instead of annually

C. The sub-brilliant subject-matter would propel betwixt the tropics fair affect it does

today

D. There would be no sub-brilliant subject-matter

III. Rotation

Earth thoroughs one order almost total 24 hours. This order is what

gives us days and nights.

Double-click Foe of Illumination. This emblem shows the foe of sunshine,

or the day-night superscription, for June 21.

At 9:00pm EST in New York, South America is in ignorance, suitableness North America is

still in day unsteady. If we accelerated obtrusive 2 hours to 11pm EDT in New York, the foe of

sunshine has propeld westward. Indeed, the Earth’s order aids enumerate the

Sun’s spectre is spdecipher counteract the Earth’s manner.

Question 23: Assume the Earth was tilted and revolved, but did not agitate.

What would the periods be affect if the Earth did not agitate?

A. No fluctuate to the floating periods/seasonality on Earth

B. There would be one period on Earth

C. There would a steady summer-type period on one face of Earth and a

steady wane-type period on the other face of Earth.

D. Earth would test a summer-type period (delay sunlight) for encircling 6

months and a wane-type period (delay no unsteady) for encircling 6 months

Click Back to Google Earth, which is located in the top-left nook in the

We are now going to go through one order on Earth.

Zoom out as far as you can until the Earth is as balance as Google Earth allows.

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Click Show sununsteady acrosss the anticipation ( ). A interval description displays at

the top of the slide bar. (Note: Verify that the Historical Imagery is off

accordingly it can cloke the Show sununsteady acrosss the anticipation slide bar).

Using your mouse, establish the cursor on the Earth and propel it environing until the

Sun is aftercited the Earth. Then, set North in the want lie (crush N).

Question 24: How does the foe of sunshine seem to the fraction of the

Earth floatingly confrontment you?

A. The fraction of the world confrontment me is illuminated

B. The fraction of the world confrontment me is not illuminated (shadowed)

C. The western fraction of the world confrontment me is illuminated

D. The eastern fraction of the world confrontment me is illuminated

Move the slide bar sluggishly counteract the contiguous 24 hours.

Question 25: What is the superscription of Earth’s foe of sunshine?

A. Predominately westward (just to left)

B. Predominately eastward (left to just)

C. Predominately northward (ground to top)

D. Predominately southward (top to ground)

Turn off Show sununsteady acrosss the anticipation ( ).

Collapse and unrecrush the REASON FOR SEASONS folder.

NDVI

Expand the NDVI folder.

This folder contains a course of images showing Normalized Destruction Vegetation

Index (NDVI) for the year 2011. NDVI is a not-absolutely incomplex way of dismunificent where

vegetation is most unpractised, which media that the vegetation is active and producing

greenness from its leaves and other insert ability. In unconcealed, the blacker the unpractised is

for a absorbed area, the further vegetation ccounteract and/or augmentation exists for that area.

In this individuality you procure be seeming at three dregss – Africa, North America, and

Southeast Asia. To set-on-foot, let’s go to North America in January.

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Double-click North America.

Remember that in the Northern hemisphere, the Sun is inferior in the sky in January,

and thereby assent-tos short trodden sununsteady (brilliant spectre). As a effect, the unpractised

appears listless at upper lips.

Systematically click through the months (January through December) and music

the unpractised areas in North America. (Note: The images command accept some interval to

load; as a sketch, cycle through the months partially rather than repressing all of

them at one interval).

Question 26: Which of the forthcomings months is the priority of North

America black unpractised?

A. January

B. April

C. July

D. October

Question 27: How does this month (you primeeded in Doubt 25)

fit to the sub-brilliant subject-matter of the Sun?

A. The sub-brilliant subject-matter nigh the equator

B. The sub-brilliant subject-matter nigh its most northern lie

C. The sub-brilliant subject-matter nigh its most southern lie

D. The lie of the sub-brilliant subject-matter does not matter

Double-click and primeeded Africa.

Systematically click through the NDVI months (January through December) and

music the unpractised areas in Africa.

Question 28: In which of the forthcoming month is the ample unpractised

(vegetation) area gain furthest South?

E. January

F. April

G. July

H. October

Question 29: How does the northernmost subject-matter fit to the sub-solar

subject-matter of the Sun?

A. The sub-brilliant subject-matter is counteract the equator

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B. The sub-brilliant subject-matter is at its most northern lie

C. The sub-brilliant subject-matter is at its most southern lie

D. The lie of the sub-brilliant subject-matter does not matter

Double-click and primeeded Borneo.

This is the island of Borneo (center) and the exclusive islands that produce up the

Philippines (to the north) and Indonesia (to the south) in Southeast Asia. The island

Systematically click through the NDVI months (January through December) and

music the unpractised areas in Borneo.

Question 30: What is the counteractall tend in NDVI for the year?

A. The NDVI is differentively inferior in March

B. The NDVI is differentively upper in September

C. The NDVI varies balance counteract the perfect year

D. The NDVI is differentively inferior in December

Question 31: Delay reference to Sun propensity, why do we see such an NDVI tend

for the island of Borneo? (Choose the one that is inexact)

A. There is balance departure in Sun propensity accordingly Borneo is at the equator

B. Borneo basically assent-tos the selfselfcorresponding totality of brilliant radiation year round

C. Borneo assent-tos raindroop throughout the year

D. Few, if any clouds, darken the Sun from Borneo year round

Collapse and unrecrush the NDVI folder.

ANALEMMA

An analemma is a chart that you use to mark the Sun’s slope and to

enumerate the equation of interval. The Sun’s slope is the lip of the Sun’s

brilliant subject-matter for a absorbed limit. The Sun’s brilliant subject-matter is the where the Sun is at-once

aloft (90°) at balance brilliant interval.

The Earth’s deflection is suggestive and, as a effect, revolves environing the Sun at varying

speeds depending on the interval of year. In June and July, the Earth revolves sluggisher,

compared to December and January. Hence, as the hurry of office varies, we

insufficiency the equation of interval to enumerate the destruction betwixt observed brilliant interval

(the interval when the Sun is at its pre-eminent subject-matter in the sky for your dregs) and

actual interval:

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● If the Sun is at its pre-eminent subject-matter antecedently noon (12:00pm), then the interval is

said to be Sun-fast.

● If the Sun is at its pre-eminent subject-matter aftercited 12:00pm, interval is said to be Sun-slow.

An analemma procure state us how accelerated (or sluggish) the Sun is not-absolute to noon.

Expand the Analemma folder and then click Introduction to vision the

I. Sun Angle

Expand Sun Angle.

Assume we are in Atlanta, Georgia, USA (33.95°N, 83.32°W). This city is in the

Northern hemisphere. It besides implements considerableness reluctant interval, so “noon” is

technically at 1pm. Using the illustration in the alertness, we can decipher the graph to

enumerate the Sun’s slope on August 1 is 18°N. In other opinion, the Sun is

at-once counteracthead (Sun’s brilliant subject-matter) at 18°N. However, we are not located at 18°N

but farther north at ~34°N. This media that the Sun is not at-once counteracthead but at

an propensity, disclosed besides as an eminence propensity or brilliant amelioration propensity. So what is the

Sun’s eminence propensity at its pre-eminent subject-matter in Atlanta, Georgia (~34°N) on August 1?

To acceptance this doubt we can use the forthcoming equation:

Altitude Propensity = 90° - lip ± slope

When our dregs and the Sun’s slope are in the selfselfcorresponding hemiworld (North or

South), we add the slope prize in the equation. When they are in opposite

hemispheres, we aftercited a whiledraw the slope prize. In our illustration then, we are in the

selfcorresponding hemisphere, so we add. We apprehend our lip is 34 stations and the

slope is 18 stations, so acceptance is:

Altitude Propensity = 90° - 34° +18° = 74°

Altitude Propensity = 74°

So, on August 1 in Atlanta, Georgia, the Sun propensity at its pre-eminent subject-matter would be

74°.

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Suppose we were in Cape Town, South Africa (33.92°S, 18.45°E) on August 1.

Rounding the lip to 34°S, what is the Sun propensity at noon?

Altitude Propensity = 90° - 34° - 18°

Altitude Propensity = 38°

As we can see, the Sun’s eminence propensity on August 1 at noon is fur inferior in Cape

Town, South Africa than in Atlanta, USA.

Using this equation, acceptance the forthcoming doubts.

Double-click and primeeded Dregs A.

Question 32: What is the lip (degrees simply) for Dregs A?

A. 0°E

B. 0°S

C. 78°W

D. 78°N

Question 33: What is the Sun’s eminence propensity for Dregs A on September

21?

Altitude Propensity = 90° - lip ± slope =

A. 90° - 0 – 0 = 90°

B. 90° - 90 + 0 = 0°

C. 90 – 78 – 0 = 12°

D. 90 +78 – 0 = 168°

Double-click and primeeded Dregs B.

Question 34: What is the lip (degrees simply) for Dregs B?

A. 68°E

B. 68°N

C. 133°W

D. 113°N

Question 35: What is the Sun’s eminence propensity for Dregs B on December

21?

Sun Eminence Propensity = 90° - lip ± slope =

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A. 90° - 68 – 22 = 0°

B. 90° - 68 + 22 = 44°

C. 133 - 90 - 22 = 21°

D. 113 - 90 -22 = 41°

II. Equation of Time

In importation to determining the Sun’s eminence propensity of a absorbed lip, we can use

the analemma to enumerate the interval at which the Sun is at-once counteracthead for a

absorbed limit.

Click Equation of Interval and vision the alertness.

On May 1, the equation of interval is 3 minutes Sun–fast, balanceing the Sun gaines its

pre-eminent subject-matter 3 minutes antecedently noon (11:57 AM).

Question 36: Is the equation of interval Sun-accelerated or Sun-sluggish on the March

equinox? By how multifarious minutes?

A. Sun-accelerated by 4 minutes

B. Sun-accelerated by 12 minutes

C. Sun-sluggish by 8 minutes

D. Sun-sluggish by 0 minutes

Question 37: What interval does the Sun gain its pre-eminent subject-matter on November

25?

A. 12:00 + 16 minutes = 12:16 PM

B. 12:00 - 13 minutes = 11:47 AM

C. 12:00 - 16 minutes = 11:44 PM

D. 12:00 + 13 minutes = 12:13 PM

Question 38: What interval does the Sun gain its pre-eminent subject-matter on June 15?

E. 12:00 + 0 minutes = 12:00 PM

F. 12:00 + 4 minutes = 11:56 AM

G. 12:00 - 4 minutes = 11:56 PM

H. 12:00 + 12 minutes = 12:12 PM

Collapse and unrecrush the Analemma folder. You accept thoroughd Lab Module 3.