Questions by 106

Li Ling: What causes Earth to have day and night?
A: Day and night is caused by the rotation of the Earth about its axis. At any given time, the half facing the Sun will be shined upon while the other half will have no light. Places in the former will therefore experience day while places in the latter will experience night.

Rena: What is the speed of the rotation of the Earth?

Since the circumference of the earth at the equator is 24,901.55 miles, a spot on the equator rotates at approximately 1037.5646 miles per hour (1037.5646 times 24 equals 24,901.55) (1669.8 km/h).
Ting Ting/Ker Peng: Why is the earth tilted?
A: http://sciencenetlinks.com/science-news/science-updates/tilted-earth/

Rashini: Why cant we feel the movement when the earth rotates? 
A: http://earthsky.org/earth/why-cant-we-feel-earths-spin

Thaqifah: Can we live in other planets? What is on the other planets?
A: No we can't as the other planets lack the living conditions that we need such as water, air, food and suitable temperature. The other planets are probably all gaseous, like Jupiter. This means the surface temperature would be way to high to support life, and the planets would all be of the gaseous type. None of them is likely to be solid and non would be suitable for living.

Kiev: Do all the planet revolves around the sun 365.25 days?
A: No. Saturn takes roughly 29.5 years, Jupiter roughly 12 years, Mercury roughly 88 days etc...

Justin: What does the equator stands for?
A: The Equator usually refers to theEarth's equator: an imaginary line on the Earth's surface equidistant from the North Pole and South Pole, dividing the Earth into the Northern Hemisphere and Southern Hemisphere. 

Questions by 107

Sophiann: Why is there winter? How did the temperature change to cause the four season?
A: This is caused by the tilt of the earth's axis. Northern and Southern hemisphere's each tilt toward and away from the sun during their respective summers and winters much more then areas around the equator where the angle remains much closer to perpendicular and more constant. 

As a result, areas ON THE EQUATOR receive 12 hours of daylight and 12 hours of night every day. Areas at lower latitudes & NEAR THE EQUATOR receive much closer to 12 & 12 then areas north and south of the equator.

Elijah/Zi Qi: Why does Singapore receives only summer but no other seasons?
Megan: Why is there no winter in Singapore? 
A: Because Singapore is located near the equator. Refer to explanation above.

Yu Hui: Is it only Singapore that does not have 4 seasons?
A: No: Countries that are located near the equator do not have 4 seasons.

Elina: Does North Pole have only one season?
A:Yes. They have the cold season when the sun is shining and the really really cold season when the sun don't shine.

Gavan/Delia/Jasmine: Why does the earth takes 365.25 days to revolves around the sun?
A: It takes 365 days to orbit the sun, in a normal day, but on leap year 366 days. due to the fact that we say a day is 24 hours even though it is really 23 hours, 56 minutes and 4 seconds. so we make and extra day in February every 4 years to make up for lost time.

Nicole: If the earth takes 24 hours to rotate in one complete round, how come sometimes the sky is darker on different days at the same time?
A: This depends on the time of the sun rise. In the late winter and spring season, sunrise occurs earlier each day, reaching its earliest time near summer. In summer, the sunrise time gets later each day, reaching its latest sometime around the winter season. 


Lester/Benedict: Why does the earth rotate?
A: This is due to the angular momentum of an object. The direction of angular momentum is the same as that of the angular velocity. Some scientists believe that large impacts in the early history of the Solar System may have affected the rotation of some planets. One may have caused Venus to rotate in retrograde and another could account for the 23 degree axial tilt of the Earth. The main reason that the Earth has never stopped rotating since the early periods of the solar nebula is that there is nothing in the vacuum of space to stop it. The only thing that may stop the Earth’s rotation is the gravitational forces of the Sun after it begins to expand into its red giant phase. 

Yun Ting/Yi Cai: Why did Pluto shrink?
A: It did not! It was discovered by scientist that its size is not significant enough as compared with the other planets. If we were to consider Pluto as a planet, there would be too many planets around. Therefore we classify pluto as a 'Dwarf planet' instead.

Danish: What is the diameter of the earth?
A: The diameter of the earth at the equator is 7,926.41 miles (12,756.32 kilometers).

Rachael: What is inside the earth?

A: It is made up of a core, comprising of molten rocks that is melted at a very high temperature. This will be covered in another topic in next term.

Anonymous: Why do the South Pole and North Pole have 6 months of night and day?

A: This is because, during summer, the sun is basically permanently above the horizon for half of the year, due to the tilt of the earth on its axis. If Earth was positioned upright with the Poles in a vertical position, then the North and South poles would have daytime and night-time separated by light and darkness, just like the rest of the planet. However, because it is tilted and it rotates around the sun every six months one pole or the other has to always be in the shadow. 

Calvin: Which country is night time when we wake up to go to school?

A: Read this map and figure it out!

Excellent Geography file cover pages

Mapwork

 Answers for Class worksheets

Locations of Asia countries.

Capitals of Asian countries

Class lecture on Mapwork

Maps part 1 blog from estee seetoh

Unit 2: Our Home: The Earth

Ensure that you can answer the following questions for this topic

Questions

1. Describe revolution and rotation of the earth
2. Why do we need to protect the earth?
3. Describe the inter relationships of people and the environment.

Our home the earth solar system from estee seetoh

Annoucement for test dates

Hi guys,

The Geography Test 1 will be held on the following dates:

106 and 107 : 14th Feb thursday

Topics to be tested:

Unit 2:

• Revolution and rotation of the earth
• Why do we need to protect the earth?
• Describe the inter relationship between people and the environment
• Latitudes and Longitudes
• Asia countries and capitals
• Oceans and continents

Unit 3:

• Definitions 
• Differences between human and physical environment
• Adaptation and modification to the environment

Differences between !Kung Bushmen and Singaporeans

Answers for worksheet

Qn 2. What is the difference in the sources of food supply for the !Kung Bushmen and Singaporeans?
Yu Hui : The !Kung Bushmen hunt animals for food, while Singaporeans buy food from food centres, restaurants etc.

Qn 3. Describe the different clothings between a !Kung Bushmen and a Singaporean.
Nicole: !Kung Bushmen have their clothes made of leather. They obtain it by hunting wild animals and taking their skin. They dont have much clothes on them though. However, Singaporeans buy clothes from shops and they have sufficient clothes on them, the clothes are usually made of cotton and wool.

Qn 4. Compare the types of shelter between a !Kung Bushmen and a Singaporean.
Yi Cai: !Kung Bushmen uses branches, leaves and tufts of dry grass obtained from its surroundings to build temporary shelters, whereas Singaporean uses concrete to build permanent houses.

Qn 5: What are the different types of technology (tools) used by a !Kung Bushmen as compared with a Singaporean?
Sharlotte: In Singapore, we have access to information all over the world via the internet, while in Africa, they do not have internet.
Nicole: !Kung Bushmen makes their own tools with the natural resources they can find from their surroundings unlike Singaporeans who use sophisticated guns to hunt.

Qn 6: Describe the different modes of transport between a !Kung Bushmen and a Singaporean.
Ming Xiu: The main source of transport for !Kung Bushmen is by walking, while Singaporeans' main source of transport is by using vehicles.

1a) Describe the differences between the !Kung Bushmen and Singaporeans based on its 
1ai: Access to water [2m]
Ming Xiu: !Kung Bushmen collects water from the rain and from underground sources, whereas Singaporeans have access to water supply from our taps which channels water from our reservoirs.

1aii: Types of vegetation in the environment [2m]
Danish: In Africa, the ground is mostly covered with sand, scattered bushes and long grasses. Unlike Singapore, where we plant trees and shrubs in open spaces, parks, along the roads and maintain our nature reserves where forests are protected.

1aiii: Adapting to the environment [2m]
Dong Xuan: In Africa, the weather is hot, therefore the !Kung Bushmen wears little clothing to cool themselves to adapt to the environment. Whereas Singaporeans modify the environment by turning on the air condition when they want to cool themselves.

1b: Which lifestyle do you prefer? [2m]
Jesmine Hui: I prefer the lifestyle of Singaporeans. We have air conditioning in their houses to cool themselves in the hot weather. We also have access to information from all over the world via the Internet.

1c: Describe two ways in which Man has been damaging the fragile Earth. [2m]
Elijah: We damage the earth by deforestation which is the chopping of vast amount of trees which leads to global warming. We also pollute water by ships that leak oil which have chemicals that causes the water to be polluted.

Physical and human environment: Differences between !Kung Bushmen and Singaporeans