1.33-1.35

1.33
Use the relationship between orbital speed, orbital radius and time period

Orbital speed = 2 x Pi x Orbital radius
                                time period
v = 2 x pi x r
             T




1.34
Describe how the orbit of a comet differs from that of a planet

1) Comets have sharply turning, elliptical, oval-like orbits, as opposed to the rounder, more circular shape of a   planet's orbit
2) Planets are in much shorter orbits than comets. Although a comet may pass fairly close to the sun at its perihelion it travels much deeper into space than any planets do.




1.35
Recall that the solar system is part of the milky way galaxy
   - Describe a galaxy as a large collection of billions of stars
   - State that the universe is a large collection of billions of galaxies.

Galaxies are large systems of stars and interstellar matter, typically containing several million to some trillion stars, of masses between several million and several trillion times that of our Sun, of an extension of a few thousands to several hundred thousands light years, typically separated by light years distance.

The Universe contains billions of galaxies, there are many different types of galaxy's such as Lenticular, Elliptical, Irregular, and the one that we live in, the spiral galaxy.

1.33 use the relationship between orbital speed, orbital radius and time period

orbital speed = 2x (pi) x orbital radius                                  
                          time period
   y = 2x (pi) x r          

            T

  

calculate the speed of a stellite that is orbiting 200km above the earth's surface and completes one orbit in 1h 24 min. The radius of the earth is 6400 km

EQN    V = 2(pi)r      
                       T
SUB   V = 2x(pi)x(200+6400)      
                     (60+24)x60

= 8.22 km/s

Planet	Distance from Sun (astronomical units (AU)	Time for orbit (years)	Speed (AU per year)
Mercury	0.4	0.2	12.57
Venus	0.7	0.6	7.33
Earth	1.0	1.0	6.28
Mars	1.5	1.9	4.96
Jupiter	5.0	12.0	2.62
Saturn	9.5	30.0	1.99
Uranus	19.0	84.0	1.42
Neptune	30.0	165.0	1.14

1.32 Explain that gravatational force causes...

1.31 Understand Gravitational Field strength,g,and recall that it is different on other planets and the moon from that on 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
Identify the mistake on the website!

1.30 Recall that the moon orbits the Earth and that some plants also have moons

1) How was the Moon formed?

The moon was created about 30-50 million years after the solar system. This was created through the fission of the moon from the earth's crust through centrifugal forces.
The moon was formed due to a giant impact of a mars sized body hitting the newly formed Proto-earth, this blasted material in orbit of the earth, including the moon.


2) How old is the Moon?

4.5 billion years old

3) Why does the Moon only show one side to us all of the time?

Relative to the Earth, the Moon makes one rotation every 29.5 days. That happens to also be the time it takes for the Moon to complete one revolution around the Earth.

4) The Moon is slowly drifting away from us, by how much per year?

Aprox 2.5 cm a year

5) Explain what will eventually happen to it

The moon will go into stable orbit around the earth

6) How much larger is the Sun than the Moon?

 About 416 times larger

7) How far away is the Moon?

Varies between 356500 km and 406500 km

8) What was significant about the 19th March 2011 (regarding the Moon)?

 A Super moon was seen

9) Why is there no atmosphere on the Moon?

The moon was pounded by radiation with its deformed atmosphere, causing it to be swept away. Although it might have had an atmosphere when it was young but spherical, the solar winds emitted by the sun were to strong for the moon's small gravity. And, the moon doesn't have hardly enough mass to have an atmosphere

10) Why is the gravity on the Moon 1/6th than of Earth?

 Because of the mass of the moon is less than the mass of the earth therefore the gravitational field strength is lower

11) What natural phenomenon does this ratio help to observe?

Solar eclipse 

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



youtube.com

13) How many people have stepped on the Moon? Who was the last?

12 people have stepped on the moon. The last was Harrison Schmitt

14) Why does the Moon orbit the Earth?

This is due to the earth's gravitational pull on the moon

15) How many days does it take to orbit?

29.5 days

16) What effect does the Moon have on the Earth?

 Tides in the sea

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



18) Other planets have moons, find images if those moons

19) How many moons are there in our solar system?

There are166 around the planets, and there are 122 orbiting around the asteroids.

Phases of the moon