1)At what location on earth do the stars rise in the west and set in the east? (1 mark) Explain how
Stars appear to rise in the west and set in the east on earth if someone is positioned above the Northern celestial pole.
There are two factors that cause stars to rise and set in the said manner. First, it is the northern celestial pole and second is the rising and setting of the sun. The northern celestial pole is 25 degrees away from the zenith which is to its north. So if one were in the northern hemisphere and spot a star called the Polaris, they would see it rising in the west and setting in the east. The reason for this is that the Polaris is directly above the northern hemisphere and almost exactly where the zenith is, so and since the northern celestial pole is 25 degrees away from zenith to its southern side, the star Polaris seems to look like it is on the western side of the northern celestial pole. As the sun seems to set in the west due to the earths counter clockwise rotation, this results to nightfall and therefore a person at the northern celestial pole sees the stars like Polaris to be rising from the west since as it gets darker due to sunset now the stars become visible and appear to rise from the west. As the sun now rises now from the east the opposite happens and the stars are now washed out by the sun and as they get dimmer by sunrise they now appear to set. However, stars only appear to move because of the earth’s rotation. But in real sense a proper star from any location will never appear to rise in the west and set in the east only if the universes mechanism changes or spinning of the earth changes to the opposite direction.
2) If the sun “moved” along the celestial equator instead of the ecliptic, what would happen to our
seasons? (1 mark) Why? (5 marks)
Firstly, our seasons would come to happen only because of the distance that changes between the earth and the sun. Secondly, the difference that is there between seasons would reduce and become smaller. Thirdly, one season would happen to take place on both southern and northern hemispheres all at the same time. Fourth, seasons would have days and nights having the same hours.
The celestial equator has an angle of declination that is 0 degrees and hence is not tilted. Therefore if the sun moves along it seasons would only change as a result of the distance between the earth and sun and not anything else like the difference in exposure of areas on the earth. The 0 degree angle of declination is also responsible for the same season happening on both south and north hemispheres since sun’s rays hit the earth at similar angles hence same heat and light intensities. In addition day and night will have the same number of hours during the season since movement of the sun along the celestial equator has the effect of creating equinoxes in different seasons. The suns movement on the ecliptic which has a tilt of 23.5 degrees that causes light rays to travel longer distances hence the seasons become longer but if the sun moves on the celestial equator there is no such thing as for the latter hence the seasons become smaller and reduce.
3) Give four (4) differences between the planets that lie on each side of the snow line. (6 marks)
These planets are divided into two categories namely terrestrial and Jovian planets. There are four distinct properties that these planets have that differentiate them from one another. The properties that differentiate them are states of matter in the planets, the number of moons that orbit the planets, the availability of rings around the planet, and the densities of the planets. Terrestrial planets are solid, rocky surfaces and are small in size. They have few moons and have no rings. They also have a higher density than jovial planets since they have solid or rocky particles. In addition they are close to the sun than jovial planets. Jovial planets are gaseous, with no or very little solid surfaces, and are larger in size than terrestrial planets. They have many moons and are surrounded by rings. They have a low density since they are mainly composed of gaseous matter. Moreover they are far away from the sun hence have low temperatures.
4) If a star emits energy at a wavelength of 2 x 10-12 meter and a second star emits energy at
1 x 10-12 meter, which star is the hottest? (1 mark) How did you arrive at this conclusion? (5
marks)
The star that is hottest is the one that emits energy at a wavelength of 1 x 10-12 meter. The reason behind this is that first according to physics laws all matter emit radiation in an electromagnetic form. At each wavelength the total radiation produced is dependent on the objects temperature. That is the object determines the amount of radiation emitted. Therefore objects that are hot will produce at shorter wavelengths added light while those objects that are cold will produce at longer wavelengths most of their light. The relationship that is now there is one where an objects radiation temperature and wavelength are related and hence determining the light that an object produces. This leads to what is called the intensity which is the amount of emitted light at a certain wavelength. Thus intensity peaks at wavelengths that are short while it goes down at longer wavelengths for those things that are cool. Therefore, the star with the shorter wavelength that is 1 x 10-12 meter is hotter than the one with the longer wavelength of 2 x 20-12 meter.
5) All objects fall at the same rate due to gravity. How can a massive object fall at the same rate as
a less massive one, since it would require a larger force to move the more massive one? (6
marks)
In this case well one has to apply what is newton’s second law of motion. In this law it states that force applied= mass of an object x acceleration. Therefore a massive object falls at an acceleration that is small to meet the force of gravity that is constant while the less massive one falls at an acceleration that is large due to gravity and hence in the end since the force that is acting on them is gravitational force they therefore fall at the same rate.
Works Cited
Dolma, Lisa. Astrology. London: Hodder Education ;, 2007. Print.
Leary, Denyse. What are Newton's laws of motion?. New York, N.Y.: Crabtree Pub., 2011. Print.
"NASA develops super-black material that absorbs light across multiple wavelength bands.” Defense & Aerospace Week 23 Nov. 2011: 14. Print.
Riddle, Bob. "Changing of the Seasons." Science Scope 1 Mar. 2011: 13. Print.
Seeds, Michael A. The Solar system. 5th ed. Belmont, CA: Thomson Brooks/Cole, 2007. Print.
