In today's lesson we did some work on into science. Our aim was to further our knowledge on forms, sources, and energy transformations. ![]() This image above is one of the images I took from the mid challenge quiz. The question is A boy pushes a toy car along the carpet, then let's it go. The car continues to move. This is an example of: I chose the 3rd answer Transfer of energy. ![]() In the picture to the left we can see that all these things contain energy. This is known as the Law of Conservation of Energy. It states that energy cannot be created or destroyed, meaning that the energy in the universe must remain constant. During this lesson we also covered the different ways energy can transfer from one object to another. These different ways are conduction, convection and radiation. Conduction is the passing of energy from one solid object to another. This occurs when you touch a hot object. The object passes its energy directly into your hand. Convection is similar to conduction, however it doesn't occur in solid objects. Convection can only occur in gases and liquids. When one part of a glass of water is heated and the others aren't, the hot water will rise to the top because its increase in energy made it less dense than the rest of the water. These 'convection currents' can also occur in gases. Radiation travels as waves rather than as particles and can therefor travel through a vacuum. Examples of radiation are ultraviolet and infrared. We feel the latter as heat. Lesson Summary:
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Aim: To create Sankey Diagrams to describe energy transfers. Keywords: Transformation;Efficiency Definition: Energy transfer: The movement of a single form of energy from place to place or from one body to body. Energy transformation: The change of one form of energy into another form of energy. Focus question: How do we illustrate energy transformations. We can use diagrams like a 'Sankey diagram', this allows us to show how the inputted energy is used. The arrows have different proportions which shows how much energy is going in on and out through that of useful or wasteful energy. The first 'sankey diagram' is of a normal light bulb. it shows that there is 100j going into the bulb, only 75% gets turned into light energy and the other 25% into wasted heat energy. Now if we do the math that means that the light bulb is running on a 75% efficiency rate because 75% of the energy is used for productive purposes. The second sankey diagram is that of an LED(light-emitting diodes). This diagram shows that there is 4j going into the bulb, and this shows that 3.2j or lost to heat energy. Then it shows that 0.8j or transferred into light energy. After doing the math we can see that the LED has an efficiency rate of 20%. So you could argue the question, why are people switching to LED? The answer has many components that sway it both ways but if you have money in your pocket it is a definite yes. This is because the LED's last 25 times as long as normal light bulbs, they also produce less heat energy which puts less stress on air conditioners. The final reason is that it costs a 25th of the cost to run the lights. In today's lesson our teacher taught us how to draw a 'sankey diagram'. Below in the images are my drawings. Lesson Summary:
Aim: To distinguish between the forms of energy and sources of energy. To classify the different forms of energy Keywords: Kinetic, Potential What happens to energy: Energy can neither be created nor destroyed, but it transfers from one form to another. When looking at the sheet we can see that when we put energy into something, energy comes out. The energy that has come out has been converted into useful and non-useful energy. For example when energy is put into a chain saw, kinetic energy is produced as a useful energy but heat and sound are also produced as wasted energy. How does Potential gravity work? By looking at the image below, it shows how potential gravity works and how it is released. As the cart moves across the roller coaster tracks the energy is used up. At the start of the roller coaster, the cart has maximum potential gravitational energy. This is because the cart is at the highest point on the roller coaster. At the bottom of the hills there is maximum kinetic energy but when the cart starts to move up the track, it loses the kinetic energy due to air resistance and track friction. By the end of the run, the car has lost all of its kinetic energy because of the friction. By looking at this we can see that the gravitational energy has not disappeared, it has just transformed into heat energy due to the friction. Lesson Summary:
Aim: To investigate how to make a cotton reel car move, using potential energy. Keywords: Elastic potential energy How cotton reel cars work most efficient:
When using the cotton reel cars our team realised that the tighter we wound the rubber band, The longer and faster the car moved. But there was a tipping point where if you wound it too far it would tip over and stand instead of rolling. This is because the tighter wound the rubber band is, the more elastic potential energy is stored ready for use. Lesson Summary: In today's lesson our group learnt:
Aim: To distinguish between forms of energy and source of energy; to classify the different forms of energy. Kinetic or potentital. Key words: Kinetic, Potential Focus Question: What is energy? Energy is the ability to do work. (To make a change happen). Definitions: Sources: Where we get the energy from. Such as sun, coal, wind and oil. Forms: The kind of energy that we can observe such as light, heat and movement. Gravitational - the potential energy held by an object because of its high position compared to a low position. Chemical - energy stored in the bonds between atoms that is released by a chemical reaction. Nuclear - the splitting of uranium atoms to create energy by fission. Elastic - the energy stored by stretching an object. Motion - the kinetic energy an object has due to its motion. Heat/thermal - the kinetic force of the hot, fast moving atoms. Electrical - the kinetic energy that comes from charged particles which forms electrical current. Sound - the energy coming from the vibration of matter. Light - is energy that travels by waves or particles. Below are some images from the lesson. First was Izaak's sheet Then my sheet from today's lesson. Lesson Summary:
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AuthorStudent from St Augustine's College in Brookvale, NSW ArchivesCategories![]()
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Photo used under Creative Commons from Tovstonog