Term 2 Notes

1. Term 2 Notes

2. The image above is the sun. The sun is a massive star which sits at the center of our solar system. The sun has a diameter of nearly 1.4 million kilometres. It has a surface temperature of 15 000 000 °C It is estimated that the sun has been burning for about 4.6 billion years and has enough fuel for another 5 billion years. Eventually the sun will burn itself out. However, this process will take a trillion years

3. The Solar System The solar system is made up of a star and all the celestial bodies (planets, meteors, asteroids, etc.) that surround it. There are eight planets in the solar system. The first four Mercury, Venus, Earth, Mars are known as terrestrial planets. Jupiter, Saturn, Uranus, Neptune are known as gas giants. They are far larger than the terrestrials.

4. There are smaller planets like Pluto, Ceres, and Eris that are known are dwarf planets. Furthermore, asteroids and meteors are much smaller than dwarf planets. Some of the larger planets have moons attached to them. Earth has one. However, some of the larger planets like Jupiter have 16 moons, Saturn has 18 and Uranus has 15. Moons vary in size between 10 and 3000km

5. Terrestrial Planets The four terrestrial planets are Mercury, Venus, Earth, Mars. These planets are mostly made up of rock and have a solid surface. They also have the same internal structure: a metallic core, a liquid mantle and a crust. These planets also have an atmosphere made up of different gasses.

6. Gas Giants The four larger planets are known as gas giants; Jupiter, Saturn, Uranus, Neptune The internal structure of these planets are relatively unknown. We do know that these planets have a solid core and a very dense atmosphere. There is no solid outer crust. Instead thick layers of very hot or cold gases surround the solid core.

7. Meteors A meteor is a sand to boulder sized piece of debris present in the Solar System. When this debris is still free moving within the Solar System it is called a meteoroid. As soon as a meteoroid enters the Earth’s atmosphere it is called a meteor. If a meteor falls to the surface of a planet and survives the impact it becomes a meteorite. All meteorites will form an impact crater

8. Universal Gravitation Why do apples fall to earth, but not the moon? What force pulls objects close to the Earth towards its center, while the moon seems to escape this attraction to the earth? Sir Isaac Newton 1642-1727

9. Newton proved that due to the sun’s large mass it is able to attract larger objects like planets, comets and asteroids towards it. Basically, Newton proved that all objects in the universe will attract one another. Objects with larger masses will attract objects with smaller masses Ex: Sun attracts the earth, earth attracts the moon. Remember universal gravitation is not the same as gravity. They are two separate forces.

10. What makes our Planet Different from others?

11. The only known planet that has life. Has a large supply of oxygen. Large supply of water. A protective ozone layer How would you describe our planet to someone or something who has never seen it before? What are some of the Earth’s properties?

12. Internal Structure of the Earth The Earth is made up of four layers. Crust Mantle Outer Core Inner Core The Earth also has an exterior structure called the atmosphere.

13. Earth’s Structure: Crust For all living organisms the crust is the most important part of the Earth. The crust houses all life present on Earth. The crust of the Earth is between 5-50km thick. The thinnest parts of the crust are the ocean floors, the thickest are mountain chains. The crust sits on top of the mantle. The mantle is liquid.

14. The crust is not all one solid piece. Over time it has broken into smaller pieces. These pieces are called tectonic plates. The crust has all of the properties that life needs to survive. It experiences changes in temperature, weather, and precipitation. It is the part of the Earth that is most effected by Global warming. It is also effected by pollution created by humans.

15. The Mantle The second layer of the Earth is the Mantle. The mantle is the thickest layer of the Earth. It extends to a depth of over 2800km. This layer is made up of liquid rock. There is incredible pressure and heat that forms in this layer.

16. The Crust floats on the top of the mantle in giant pieces called tectonic plates. These plates move around and cause earthquakes and volcanoes. The mantle is constantly in motion. This movement causes the tectonic plates scrape and hit each other, which is an earthquake. Volcanoes form when two plates crash into each other. Volcanoes are the earth’s cooling system and pressure release.

17. When two plates squeeze together and the crust moves upwards, mountains are created. This process is called orogenesis. When two plates squeeze together and one plate moves under the other, is called a subduction zone. Mountains can also be formed in a subduction zone.

18. The Core The core is the innermost layer of the Earth. It is usually divided into outer core and inner core. Although there is no confirmed theories the most probable is that the outer core is liquid metal mostly iron and nickel. With this theory scientists argue that the core is a solid ball of iron.

19. The core is the heaviest layer of the earth. It is believed that this layer give the earth it’s gravity and magnetism. Magnetism is a force. It is this force that causes compass needles to point north. This is what we call magnetic north.

20. The Atmosphere The atmosphere is a layer of gases that surround the Earth. The Atmosphere has two basic functions. To protect life on Earth. To sustain life on Earth. The Atmosphere protects Earth from UV radiation from the sun. Moreover, it burns up small pieces of debris that may fall to Earth (rocks).

21. The Atmosphere also sustains life on Earth, since it supplies us with oxygen. It also regulates climate and temperature, it keeps in necessary heat and releases excess heat. Our atmosphere is composed of 78% Nitrogen, 21% Oxygen, and 1% other gases. The Atmosphere consists of 5 layers. Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere.

22. The troposphere is the layer that is closest to the Earth. It extends about 20 km from the surface of the Earth. Humans have reached the Thermosphere with the space shuttle. However, the Exosphere is still relatively unexplored.

23. Hydrosphere The hydrosphere refers to the layer of water that surrounds the Earth. 71% of the Earth’s surface is covered by water. Most of this is found in the Earth’s oceans and seas. The hydrosphere is home to millions of plant and animal species. The hydrosphere includes oceans, lakes, rivers, streams, as well as ice and glaciers.

24. Water vapour and clouds also make up part of the Hydrosphere. The hydrosphere is responsible for the hydrologic cycle also called the “Water Cycle”. This cycle is what gives us precipitation. Water will evaporate and form into clouds, when clouds contain too much water it is released as precipitation (rain, hail, sleet, snow). This process is vital for all life on earth. Every living thing needs water to survive.

25. Lithosphere The Lithosphere is the rigid outer layer that surrounds the Earth. The Lithosphere is made up of the Crust and the uppermost part of the Mantle. Scientists include the tectonic plates when talking about the Lithosphere. The Lithosphere extends to a depth of roughly 100km.

26. Ozone Layer The Ozone layer is a collection of ozone (O3) gas. This layer is located in the lower half of the stratosphere. This layer is located between 10-50km above the Earth. The ozone layer protects all life on earth, by blocking most of the sun’s UV radiation.

27. In recent years the Ozone layer has become increasingly damaged. In fact a hole has developed. The damage comes from pollution. Specifically the increased amounts of CFC’s in the atmosphere. CFC’s are present in car exhaust, industrial smoke, and aerosols. These chemicals attack and destroy ozone molecules. What are the threats and consequences of a damaged ozone layer?

28. Hole in the Ozone Layer As mentioned above the Ozone layer has developed a hole which sits primarily over Antarctica and the Southern most tip of South America. Every year this hole is increasing in size. What are some of the possible effects of this hole in the Ozone layer?

29. Increase in the rate of Global Warming and climate change. Increased amounts of UV radiation will hit the surface of the earth. Increase in the number of people affected by skin diseases. Increase in daily average temperatures. Damage to livestock and crops. Droughts and floods Rise in extreme weather (storms)

30. What can we do to help? Reduce, Reuse, Recycle Buy energy efficient products Carpool or use public transportation Reduce your use of aerosols. Turn off of lights or other electrical appliances when they are not in use. Buy local food, organic if possible (no pesticides)

31. Rocks and Soil The Earth’s mantle and crust are responsible for creating rocks and determining the soil type of an area There are three main rock types Igneous rock: formed by magma that has cooled on the surface of the earth.

32. Sedimentary Rock: tiny particles of sand, rock, shells, called sediment that has bonded together in layers and hardened.

33. Metamorphic rock: formed deep within the crust under intense heat and pressure. Usually contains crystals.

34. Soil is part of the lithosphere. We classify soil according to; structure, texture, and color. Structure: is the amount of space between each grain. Texture: is the feel of the soil in your hands Color: can be very pale or dark. Soil and rocks are prone to erosion Erosion is the wearing away of the relief due to water, ice, wind and gravity.

35. Drawings Drawings, images, and pictures are used in our everyday lives. Drawings can be used to represent an event, action, person, or a law. In many circumstances a drawing or picture can be clearer than a verbal or written explanation. Some images have become so recognizable that no words are needed at all.

36. Types of Drawings Drawings are most often used in construction. Drawings serve to illustrate how various parts will connect with one another. Furthermore, drawings will show dimension. Finally a drawing can depict how to put an object in motion.

37. Drawings can also serve as instructions in the making of a technical object. There are three types of drawings one can use. 1) Sketch A sketch is a freehand drawing that depicts a design of an object. It will show the shape and some dimensions of an object. It will also help in the creation of other drawings

38. 2) Design Plan A simplified drawing showing the function and operating principles of an object. This type of drawing does not include any measurements or list of materials.

39. 3) Technical Drawing Is a simplified drawing showing the materials and steps to get the object to its final functioning form. It may also be necessary to include several angles (front, top, side views) This type of drawing also includes how different pieces will be connected. There are 12 basic lines that one can use in a technical drawing

40. Manufacturing Process Sheet A manufacturing process sheet is a document similar to a set of instructions. This document includes every step required to manufacture a technical object. It provides the order in which steps need to be carried out. It also gives the time allotted for each step

41. Materials, Raw Materials, and Equipment The manufacturing of technical objects requires a diverse set of materials. Material: any substance used to make things. Materials are classified by the origin of their raw materials. Materials include things like: wood, glue, staples, paper, metals, etc.

42. Raw materials: a natural material that has not been transformed into materials that can be used. Raw materials are unprocessed. There are three major categories of raw materials. Wood substances: hard and soft wood Minerals: Iron, copper, steel, etc. Crude oil: plastic, polymer, nylon, etc.

43. Equipment: are the tools, instruments, and machines that create technical objects. Equipment could be as simple as a pencil, scissors, toothpick, etc. Equipment are technical objects themselves. Every piece of equipment is made up of materials and followed a process in its manufacturing.

44. Specifications Specifications is a document that provides a detailed description of needs and demands. A technical object will have a specific function, therefore it needs to be built in a certain way. For example, a bridge must be able to withstand strong winds, precipitation, and natural hazards.