Tuesday, March 29, 2011

1.31 Understand gravitational field strength, g, and recall that it is different on other planets and the moon from that on the Earth

Questions (roll mouse over to reveal answer)
What does small 'g' stand for in the equation W = mg?
What is approximate value of 'g' on Earth?
What is approximate value of 'g' on the Moon?
What are the units for 'g'?
Why is this equation useful?
Why is 'g' different on different planets?
Which object in our solar system has the largest 'g'?
Explain why this object has the largest 'g'
Where on a planet is 'g' the greatest?
What happens to the value of 'g' as you go further away from a planet?
How does this affect your weight?
Find your mass on the bathroom scales and then find your weight on different planets (click this link: http://www.exploratorium.edu/ronh/weight/), take a screen shot and upload the image to your blog



How was the Moon formed?
There are many theories, one of them is that 4.5 billion years ago one of many planetary bodies growing hit Earth during it's growing process blowing out rocky debris. A fraction of that debris went into orbit around the Earth and aggregated into the moon.
[http://www.psi.edu/projects/moon/moon.html]

How old is the Moon?
The moon is about 4.5 billion years old.
[http://lunarscience.arc.nasa.gov/kids/age]

Why does the Moon only show one side to us all of the time?
The moon rotates at a different speed therefore we only see the same side.
[http://www.moonconnection.com/moon-same-side.phtml]

The Moon is slowly drifting away from us, by how much per year?
The moon moves away from the Earth about 3.8cm a year
[http://lunarscience.arc.nasa.gov/kids/moonform]

Explain what will eventually happen to it
As the moon gets further away the tidal effects will diminish and the rate of energy transfer will drop, the moon will not leave orbit becuase the amount of kinetic energy in the earthmoon system is not large enough to let it go.
[http://answers.yahoo.com/question/index?qid=20101205074136AAISsAm]

How much larger is the Sun than the Moon?
The sun is about 416 times larger than the Moon.

What natural phenomenon does this ratio help to observe?
Solar and Lunar eclipse.


How far away is the Moon?
The distance from the Moon and the Earth varies from 221,463 miles to 251,968 miles.
[http://www.enotes.com/science-fact-finder/space/how-far-moon-from-earth
What was significant about the 19th March 2011 (regarding the Moon)?
There was a Supermoon, the moon was 356,577 km away from Earth, the closest it's ever been in 18 years.
[http://www.24x7newsportal.com/2011/03/supermoon-19-march-2011-moon-closest-to.html]

Why is there no atmosphere on the Moon?
The Moon is smaller than the Earth therefore the gravitational force is smaller thus there is still gravity on the Moon but too little to hold a significant atmosphere.
[http://www.suite101.com/content/why-there-is-no-atmosphere-on-the-moon-a102634]

Why is the gravity on the Moon 1/6th than of Earth?
The Earth is bigger than the Moon.

How many people have stepped on the Moon? Who was the last?
Twelve people have stepped on the Moon, the last being Eugene Cernan.
[http://www.google.co.th/#hl=en&biw=1362&bih=583&q=last+man+on+the+moon&aq=f&aqi=g10&aql=t&oq=&fp=86b37ed402aae59d]

Why does the Moon orbit the Earth?
The moon orbits the earth because it is "in motion" and its inertia, coupled with the attraction of gravity, keeps it in its orbit. The same is true of the earth and sun.

 
How many days does it take to orbit?
The Moon completes its orbit around the Earth in approximately 27.3 days.
[http://en.wikipedia.org/wiki/Orbit_of_the_Moon]

What effect does the Moon have on the Earth?
The gravitational pull of the moon actually bulges the water in the oceans out from the earth's surface toward the moon. This constant push and pull tug-of-war with the oceans by the moon is what causes the tides at the beach.
[http://www.extremescience.com/zoom/index.php/space/35-space-science/77-about-the-moon]

Insert a video (and source) of the answer to the question above


Other planets have moons, find images if those moons
How many moons are there in our solar system?
Oringinally there were 9 planets in our solar system however scientists decided that Pluto was no longer categorized as a planet so there are now 8.
[http://www.universetoday.com/15568/how-many-planets-are-in-the-solar-system/]