Sun / Earth / Moon / Tide Quest

Part 1 – Critical Speed

Type the address http://sunshine.chpc.utah.edu/labs/tides/tides_main.html . Click on the image in the center of the page.  Click on Student Version.  Click on the Critical Speed Icon. Read all of the pages carefully and answer the questions below.

1)      What is the speed the Earth needs to achieve circular orbit around the Sun (critical speed)?  ________________

2)      What happens to the Earth when the speed is greater than its critical speed? __________________________________________________________________

3)      What happens to the Earth when the speed is less than its critical speed? __________________________________________________________________

4)      Is the critical speed of Venus faster or slower than the critical speed of Earth? _______________

5)      Is the critical speed of Mars faster or slower than the critical speed of Earth? _______________

Part 2 – Tide Basics

Type in the address http://www.sfgate.com/getoutside/1996/jun/tides.html . Read the whole page carefully and answer the following questions.

1)      What has a gravitational pull on the Earth’s water as it orbits the Earth? _____________

2)      What is the other massive object that has a gravitational pull on the Earth’s water? _____________

3)      When is there a neap tide? ____________________________________________________________________________________________________________________________________

4)      When is there a spring tide? ____________________________________________________________________________________________________________________________________

5)       At low tide the water level on the beach is ________.

6)      Do high tides always rise to the same level on the beach? Why? __________________________________________________________________

Part 3 – Specifics about Tides

Type in the address http://en.wikipedia.org/wiki/Tide .  Only look at the pictures on the right side of the page and read the first two paragraphs of the section called Tidal Forces.  It may be difficult to understand, but try your best.  Answer the questions below.

1)      Why is the tidal force of the moon larger than the tidal force of the Sun?

A)    the moon is larger than the sun and therefore has more tidal force on Earth’s water

B)    the moon is much closer to the Earth than the Sun and therefore has slightly more tidal force on the Earth’s water

C)     the moon has a face and the Earth wants to kiss it and therefore the Earth’s water is pulled more toward the moon

2)      The water on the parts of the Earth that are closest to the moon are:

A)    more strongly attracted to the moon by gravity than inertia keeping the water on Earth going in the same direction

B)    more affected by inertia keeping the water on Earth going in the same direction than the gravitational attraction to the moon

C)    equally attracted to the moon and moved by inertia that keeps water going in the same

direction   

3)      The water on the parts of the Earth that are farthest from the moon are:

A)    more strongly attracted to the moon by gravity than inertia keeping the water on Earth going in the same direction

B)    more affected by inertia keeping the water on Earth going in the same direction than the gravitational attraction to the moon

C)    equally attracted to the moon and moved by inertia that keeps water going in the same direction  

Part 4 – Center of Mass

Type in the address http://en.wikipedia.org/wiki/Center_of_mass#Animations . Only look at the animations and answer the questions.

1) If the red cross in the middle of the animations represents the center of mass, is the center of mass closer to the Earth (larger body) or the Moon (smaller body)? ________________________

2) When the Moon “rotates” around the Earth is it really rotating around the Earth or is it rotating around the center of mass?  ________________________________________________________________________

3) Does the Earth move or stay still when the moon “rotates” around the Earth?

________________________________________________________________________

Part 5 -  Tide Simulator

Type the address http://sunshine.chpc.utah.edu/labs/tides/tides_main.html . Click on the image in the center of the page.  Click on Student Version.  Click on the Tide Simulator Icon. Read all of the pages carefully and answer the questions below.

1)      What moves toward the moon because of gravitational pull from the moon?

_____________________________________________________________________

2)      When do the oceans deform the most?

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3)      Explain why the oceans closer to the moon are pulled towards the moon and why the oceans farther away from the moon want to travel away from the moon?

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4)      Why does the sun, which is much larger than the moon, have less of an affect on the moon’s tides?

A)    When mass increases gravity increases, but tidal effect decreases.

B)    Tidal effect is not related to gravity

C)    The moon is further away from the Earth than the Sun

D)    For tidal effect, two objects located close together is more important than the strength of gravitational force.

Part 6 – Putting It All Together

1)      Now you know a lot about gravity, centripetal force, center of mass, and the motion of the Earth, Moon, and Sun.  Describe why there can be high and low tides on different parts of the Earth.   Use words and a drawing to show you understand tides.

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2)      Describe what causes a very small high tide and a very small low tide on Earth.  Use words and a drawing to show you understand the answer.

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3)      Describe how tides would be affected if Earth had no moon?  Draw a picture too.

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Part 7 – Tide Level Observer

Type the address http://sunshine.chpc.utah.edu/labs/tides/tides_main.html . Click on the image in the center of the page.  Click on Student Version.  Click on the Tide Level Observer Icon. Use the Tide Level Observer to answer the questions below.

1) On a typical beach on an ocean, how many times does high tide occur and how many times does low tide occur during one day?

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2) Knowing the answer to question 1 and everything you know about tides, try to figure out about how many times the moon rotates around the Earth in one day.

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Part 8 – Research (If you have time)

On the internet research the answers to the following questions.

1) What place on the Earth does the water level change the most because of tides?

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2) What are tides pools or estuaries?

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3) What are some interesting facts about animals or plants that live in tide pools or estuaries?

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