EM Goals!

Introduction:

For the past few weeks we have been working on twelve of our EM topics. They were mostly about magnetism, since electricity goals have already been covered, but magnetism has a very clear connection with electricity and that is why, it also shows. I had a very hard time understanding some of these topics, due to the fact that I had not learned before any of this before. After reading the textbook and asking my friends and teacher for help, I actually understood the full meaning of most of the topics mentioned in this blog post. I hope this will help other people with difficulties to understand and also that you enjoy it.

EM9. I can describe the properties and interactions of magnets: Opposites poles attract. Magnets attract materials made from Iron, they point into one direction (if are allowed to move freely.

EM10. I can describe how the magnetic domains are arranged in a magnetic/non-magnetic material: The domain in a magnetic material is arranged so that the atoms are all pointing at one same direction. In non-magnetic materials, atoms point in different directions, which is the cause of their non-magnetic properties.

EM11. I can explain the connection between electricity and magnetism (electromagnetism): An electromagnetism is when an electric current produces a magnetic field. Whenever there is electricity there is magnetism.

EM12. I can outline the difference between DC/AC current and its uses: The direct current goes continuously and the alternating current the charges flow back and forth in a circuit. The DC current is used in objects such as batteries and the AC current is mostly used for sending electricity to homes and buildings.

B Goals

EM13. I can explain why the Earth behaves like a magnet and the consequences of it: The Earth has a north and a south pole. They create a magnetic field around the Earth and protect all the living things from particles coming from the sun. (solar wind)

EM14. I can explain the importance of grounding wires and using fuses/circuit breakers: The grounding prong is used as a safety measure to protect people from short circuits or in other words a shock. It provides an alternate path or the current straight to the ground. A fuse is a device connected to a circuit, which contains a thin strip of metal, that will detect when there is a lot of current and melts.

EM15. I can explain how an electromagnet works and cite applications for them: If you make a current flow, it can be turned on and of. They are used to lift up cars in the car junk, they are also found in railways for the metro, since they have to go fast and literally are lifted from the ground.

EM16. I can explain how a simple motor works (parts and function): The battery creates a current that will be led through the brushes to the comutator. After this the current causes the armature to spin, this movement causes the current to inverse. The product of this is mechanical energy. The comutator rotates in the direction of the current, making the armature spin. The armature’s magnetic field interacts with the permanent magnet. The brushes conduct the current to the armature.

http://www.sciencebuddies.org/science-fair-projects/project_ideas/Elec_img136.jpg

EM17. I can describe how a generator and a transformer work: The generator transforms mechanical to electrical energy. A generator uses motion in a magnetic field to produce an electric current.  A transformer is a device that increases or decreases voltage.  When the primary coil has fewer loops than the secondary-coil it is a step-up transformer and the step-down is the other way around.

http://www.energex.com.au/switched_on/images/project_info/electricity_production/45.gif

EM18. I can explain the importance of transformers to power grids:  The boxes in the power grid contain transformers, they are important there because of the following: The energy is send with a higher push, so it will get to the houses and buildings in a short amount of time. In your house the voltage is regulated to be either 110v or 220v, the transformers are there to adapt the voltage to the one in your house.

Transformer:

http://www.electricityforum.com/images/electrical-transformer-design.jpg

EM19. I can explain methods of power production and distribution: Hydroelectric Energy- From mechanical to electrical energy. Nuclear Energy- from nuclear to thermal, to mechanical, to electrical energy. Fossil Fuels- From chemical to electrical energy. Biomass- From chemical to thermal, to mechanical to electrical energy. Solar Energy- From electromagnetic to electrical energy. Wind Energy- From mechanical to electrical energy. Geothermal Energy- From thermal to mechanical to electrical energy.

EM20. I can describe the differences of 110v/220v and main advantages and disadvantages of each: 220V is more powerful than the 110v. Having installed 110v in your house makes it less probable to cause an accident; also most appliances are 110v, so it would be more practical. Having a high probability of an accident is a disadvantage of 220v, but in compensation, it is more cost efficient than 110v.

EM21. I can describe the advantages and disadvantages of electrical energy: Advantages- Practical, used to power up most things and easy to transport. Disadvantages: It is expensive and can be very dangerous.

                                                                                                                                                                                     

Conclusion:

After understanding the topics, I found the subject a little bit easier than I did at the start. After reading, asking and writing, the abstract images came clear in my mind and I hope they do stay this way. Apart from the fact of not understanding, the only other problem I had was the vocabulary, for example, I did not know what power grids were, neither grounding wires, fuses and circuit breakers, but with help of my friends and of the internet I understood all of the concepts and was able to answer what the objective asked for. 

First two weeks!

Last semester in our science class we learned about cells, measurements and genetics. This month, however we are studying electricity and magnetism, we have done many fun activities to be able to understand both these subjects. We started out with electricity and for that we build a simple electric motor, for magnetism we build an electromagnet using a simple nail, short amount of wire, two paper clips and a battery. But that was not all! We were then divided into groups of three and were each given a different topic of revision. These topics were covered in seven grade and we used this time to review the terms and learning goals.

Simple Electric Motor: The electric motor project was given to us as a starter to our new subject. Most of us did not know anything about it or had any idea on how to build it, but we used our sources and were capable to build the motors. In my case I watched videos and read about them on the Internet. Building the motor was very challenging, but it was easier to comprehend how it worked: The electric charge caused by the battery flows through the paper clips and on to the wire, but this is not all since this is not what causes the circle made of wire to spin. The magnet under the wire creates a magnetic field causing the wire to spin. Here is the picture of a simple electric motor that looks like mine:

http://www.google.com.br/imgres?q=simple+motor&hl=pt-BR&biw=1073&bih=704&tbm=isch&tbnid=4-3WfQxEoiOa9M:&imgrefurl=http://www.kidslovekits.com/projects/Magnet_
Motor_kit/index.html&docid=zim_amxkxGPYRM&imgurl=http://www.kidslovekits.com/projects/Magnet_
Motor_kit/Magnet_Motor_LL.jpg&w=443&h=289&ei=Xp9CT6u_C8Pi2QXPl5muDA&zoom=1&iact=hc&v
px=538&vpy=412&dur=1101&hovh=181&hovw=27
8&tx=157&ty=108&sig=109156476607484567813&page=1&tbnh=164&tbnw=240&start=0&ndsp=12&ved=0CGoQrQMwCg

Building an Electromagnet: We were then put into groups of three and build an electromagnet; this is a special type of magnet, since it can be turned on and off and it is usually used to transport something heavy, for example the cars in a car junk. This is how it works: The wire is rapped around the nail and connected to the battery. As the ends of the wire touch negative and positive on the battery, the metal part of the nail becomes a magnet that attracts the paper clips. As soon as you disconnect both ends of the wire from the battery the paper clip droops from the nail.

http://www.google.com.br/imgres? q=electromagnet&hl=pt-BR&sa=X&biw=1073&bih=704&gbv=2&tbm=i sch&tbnid=fkLoqGFzINHWSM: &imgrefurl=http://hilaroad.com/ camp/projects/magnet.html&docid=GYy3geC0BgVJvM&imgurl=http://hilaroad.com/camp /projects/electromagnetism/electromagnet_battery.jpg&w=640 &h=346&ei=JKJCT96OAc_o2gW59ayhCA&zoom=1& iact=hc&vpx=105&vpy=176&dur=3324&hovh=165&h ovw=306&tx=247&ty=95&sig=109156476607484567813&page=1&tbnh=128&tbnw=236&start=0&ndsp=13&ved=0CEIQrQMwAA

Goals:

1) How do electric charges interact?

The first revision goal was to answer the question: How do electric charges interact. Just as magnets, electric charges have negative and positive and they interact in just the same way. Positives repel positives, negative repel negative and positive and negative attract. All of the charge objects have an electric field around them, of course we cannot see them but they are very important on the interaction of charged objects. The closer the objects get, the stronger the electric field becomes.

2) How are charges transferred between materials?

There are three ways through which charges can be transferred. These are induction, conduction and friction.

In Friction two objects rubbing against each other transfer the charges. The object that loses the electrons becomes positive and the one that receives it becomes negative. An example of friction in real life is when you rub your sock against the carpet; your sock will have more negative charges than the carpet.

Conduction is when charges are transferred from one object to another by touching. In conduction the object with the biggest amount of positive charges will be the receiver of the negative charges of the other object.

Last but not least there is Induction, induction is the transferring of a certain charge to another part of the object because of the electric field around the second object. In induction the contact between the objects is not needed or seen.

3) How is an electric current produced?

“An electric current is the continuous flow of charges through a material” (pg. 45) Voltage is the one responsible for the production of electric currents, but the electric circuits are also very important since the charges flow continuously through these circuits consequently causing and creating an electric current.

4) I can compare conductors with insulator

Conductors: Materials that are conductors transfer energy faster; this is caused because the electrons in a conductor are able to move freely. Silver, aluminum and copper are examples of conductors. A wire is usually made of a conductor, since it allows charges to flow through easier and faster.

Insulators: Materials that are insulators decrease or stop the flow of charges; this is because the electrons in an insulator are bound together. Rubber, sand and wood are good examples of insulators. When there is a rubber protection around a copper wire, it is there to stop the current from the conductor to give you a shock.

5) How does resistance affect current?

For the current to work it depends not only on the voltage, but also on the resistance. The resistance is the difficulty that the charges have to flow through.

There are four factors affect resistance:

The first factor that affects resistance is the material of which the resister is made. If the resisters in a circuit are made of insulators it is efficient, since the insulator makes it harder for the charges to flow.

The second characteristic is the length of the wire, the longer the wire, the stronger the resistance.

The width of the wire also affects the resistance. In this case if the wire is wide the resistance will decrease, so if you want a good resistance the best one to use would be a thin wire.

The last feature of resistance is heat. If the wire is hot, the resistance is high and if the temperature decreases so does the resistance.

6) Use ohm law to calculate resistance, voltage or current

Ohm wanted to test the relationship between resistance, voltage and current. For this he build a circuit with a voltage between two different points of a conductor, he then measured how resistant the conductor was and finally calculated the current between the two points. With his results he found out that: resistance = Voltage/ Current.

7) How do you build series and parallel circuits?

There are two different types of circuits; there is the series circuit and the parallel one.

Series Circuit: The series circuit has only one path trough which current can be taken. This has disadvantages, since if one of the resisters or light bulbs breaks down the other ones will also stop working, since the current needs to get through one light bulb to get to the next one for the charge to keep flowing.

Parallel Circuit: The parallel circuit has different ways on which the charges can flow through. Each of these paths has their own resister or light bulb, so if one of them breaks down or simply stops working, the charges would change their way and flow through the other resister, causing it to keep working and not break the current. In parallel circuits the light bulb are usually brighter than in a series circuit. 

Series:

http://www.google.com.br/imgres?q=series+circuit+diagram&hl=pt-BR&gbv=2&biw=1073&bih=704&tbm=i
sch&tbnid=bkXuk_6uf6MA2M:&imgrefurl
=http://www.bbc.co.uk/schools/ks3bitesize/science/energy_electricity_forces/electric_current_voltage/revise4.shtml&docid=1cATALom_C-ByM&imgurl=http://www.bbc.co.uk/ks3bitesize/science/images/circuit1.gif&w=516&h=240&ei=S6NCT9aMFeT42gXg6fSvCA&zoom=
1&iact=hc&vpx=728&vpy=448&dur=338&hovh=95&hovw=204&tx=198&ty=138&sig=1091564766074845
67813&page=1&tbnh=90&tbnw=193&start=0&ndsp=13&ved=0CHIQrQMwDA

Parallel: 

http://www.google.com.br/imgres?q=parallel+circuit+
diagram&num=10&hl=pt-BR&gbv=2&biw=1073&bih=70
4&tbm=isch&tbnid=ZFrk4TxZhm87jM:&imgrefurl=http://kimberleyparkss
.eq.edu.au/home/jmann30/science.html&docid=bQuauwnd1jIpXM&imgurl=http://kimberl
eyparkss.eq.edu.au/home/jmann30/Website%252520pictures/parallel1.gif&w=423&h=356&ei
=96NCT8bdJ4XY2QXS7JSDCA&zoom=1&iact=rc&dur=282&s
ig=109156476607484567813&sqi=2&page=1&tbnh=161&tbnw=191&start=0&ndsp=12&ved=0CFkQrQMwBg&tx=127&ty=1
14

8) Explain the relationship between power, voltage and current

Power is the transformation of energy from one form to another. Power is used al over us, in our hair driers, televisions, alarm clocks, stove, microwave, refrigerator, computer, clock radio and many others. Watts (W) is the unit used to measure power. For example, a socket can be 110W or 220W, so you have to be careful as to which devices can be plugged in each of the sockets. The formula for calculating power is: Power= Voltage X Current.

Reflection: When we first got the motor project, I will confess I was a little bit scared, since even though it looked easy to build it was not. I had many problems with my motor. I changed the material many times: the wires, the battery and the paper clips, but not even that worked. I asked many people to help me but it was still challenging. I did manage to understand what was wrong with my motor and it finally did move.

The electromagnet was easier to build, but harder to understand how it worked, I still have doubts but the basics are clear, especially because of the examples given in class.

The revision goals were also very hard for me to understand. The concepts and basics of each one are easy for me to explain, but when they go more into depth I am completely lost. I am studying and created many outlines, which helped me loads as to understand the basics of all eight goals.

In general, these first two weeks of Science Class were full of projects and revisions that helped me remember and comprehend many energy related subjects, but I do believe I could go further and study even harder to have no problems with this wonderful subject.

I hope you ENJOY! 

https://docs.google.com/spreadsheet/viewform?pli=1&formkey=dFlveXd3Z2hQSzZrNWFReTlsR2dockE6MQ#gid=0

Gas Laws Experiment

In Science Class we have moved from Biology to Physics and have already started of on Gas Laws. We did an experiment on which we had to use a syringe and five book. We then had to measure the pressure and volume each book had on the syringe and scale. At the end when all groups had their results we had to exchange them with two other groups, these are the results:

Table:

Graph:

Conclusion:

When we had all of the results, graphs and tables done, each one of us had to discuss the connection or relation between our results for Volume and Pressure. We figured that as the volume decreases the pressure tends to increase, and it sure does. We then had to read several pages from our science book and research about gas laws. After we had that done we had to analyze each of the gas laws to find out which one we are studying. At the end we concluded we are studying Boyle´s law. Boyle said that as the Volume goes down; Pressure goes up, which is extremely similar to our results. We also had to compare Boyle´s Law Graph to ours. Here is a picture of Boyle´s Law Graph:

http://www.google.com/imgres?q=Boyle%27s+law+graph&hl=es&sa=X&gbv=2&biw=1280&bih=699&tbm=isch&tbnid=FuMA9hydeUNyyM:&imgrefurl=http://resources.yesican-science.ca/trek/NEEMO/final/gas/key_gas_assignment3.html&docid=qs0EkLzymWCKzM&imgurl=http://resources.yesican-science.ca/trek/NEEMO/final/images/boyles_law.jpg&w=420&h=320&ei=6g23TtC2MJOItwfFuK3UCw&zoom=1&iact=hc&vpx=619&vpy=331&dur=545&hovh=196&hovw=257&tx=121&ty=99&sig=116542400754868332726&page=1&tbnh=153&tbnw=193&start=0&ndsp=15&ved=1t:429,r:7,s:0

It is pretty similar to the one our group got, which is one more evidence to the Gas Law we are studying and probably will be learning about it loads more later one or in the future classes. Apart from having it´s broken syringes and lose caps, the experiment was fun and learning how to find out scientific facts on our own was awesome too. I loved it and hope to do it again!

ADVETURE WITH CELLS!

For my project I decided to do a Story. I unified all of the information I had and decided to do an adventure. Below you will find more details about my project

Project Goal: My goals were to mainly show all of the essential ideas of the units and chapters about nutrients and cells. I also focused on presentation, dividing it in paragraphs, chapters according to what happens in the story. I wanted to do the drawings from the characters but I thought it was better to let the kids imagine each one of them as they wanted to.

My Plan: My original plan was to create a travelling brochure, as if the people were traveling to the cells. But then I decided to change to something I would be able to do with joy and that would be better. I love writing, so I started to write a story, a story with three characters and scenes.

What went wrong:  The first thing was that I changed projects, from a traveling brochure to an adventure story. Another thing that changed was the fact that I would draw all the characters, but when I read a book or story I love picturing them by myself, and I wanted the little kids to able to that as well. The last thing I switched were the names of the Chapters, actually I included Chapter. I thought it would be better and less messy if the paragraphs were organized.

What I Created: I created an adventure story. The main character is a Ribosome and his name is Ricky. It is basically his travel out of the Eukaryotic Cell into the Prokaryotic Cell, there he meets Rebecca and her Mother. The ending is a secret and the story full of amazing and important information.

Personal Conclusion: I think my story is coherent and contains almost all that we studied during these units about Nutrients and Cells, I also put in my imagination and creativity and made it my own!

EGG LAB POST!

In Science class we started learning our new topic, cells. After clarifying all of our doubts and question on the types of cell and their organelles, we moved on to a little more complex subject: Active and Passive transport of solutes and water between a cell and its environment. A week later though, we moved in to a more specific subject, the types of each transport, there is diffusion, facilitated diffusion and osmosis. Osmosis is just like diffusion, but only for water. Unfortunately this subject was indeed complex and specific so our teacher got us, the class, to do an experiment in which we used an egg membrane to represent an actual cell membrane and see how diffusion and osmosis really work.  

Predictions:

First we were put into groups of three members, we were then given six solutions to choose from (the eggs would later be dipped into the two chosen solutions): corn syrup, alcohol, distilled water, salty water (20% of salt), salty water (10% of salt) and tap water. My group chose distilled water and salty water (20% of salt). After all of this first process, we had to sit down in our groups and make predictions of what would happen to our eggs after being dipped into the chosen solutions for three days. My group came up with the following:

For the Distilled water we used our science knowledge to predict what would happen to the egg. Distilled water is pure water, not the one that we drink, pure water, with no minerals of solutes, because of this it makes it easier for the water to get inside the cell, causing it to fill up with water and consequently burst. Since we had this piece of information in our hands we predicted that since the egg acted like a cell, the water would go through it with no problem and eventually it would grow and consequently burst.

On the other hand, for the salty water we thought the opposite would happen, since the water has to balance between the inside of the cell, in this case the egg, and its environment. Since the water in which the egg was dipped in had salt, my group thought the water from inside the egg would come to the outside to dissolve the salt on the outside. Unfortunately this time we were wrong, the egg increased in size and by the touch of a sharp point, popped. We then sat down with each other to think of why this had happened, we then came to the following conclusion: There was even more solute inside the egg than in the salty water, so to balance both sides the water from outside the egg started to move inwards so that it could dissolve the solute inside the egg.

What we had to do:

On the first day our teacher did us the favour of putting the eggs in vinegar, we had to leave them there for 24 hours so that the egg shell would be easier to take off, this way we could work directly with the egg membrane (Be careful not to squish the egg too much, because the membrane is extremely sensible and may pop or burst). After this we had three days in a row to check both our eggs. In our groups we decided to name our eggs, but that is just a curiosity. Every day we had to follow exact steps and get the same measurements. After taking the egg out of the plastic cup which contained the liquid solution, we measured the amount left of liquid inside the cup with a graduated cylinder. Following that we took our eggs to the scale to see how much they were weighting. The third, but not last step was to measure the circumference of the eggs, for this we used a sting and a ruler. Last but not least we observed the egg and wrote down it´s physical characteristics. On the last day we were told to exchange results with other groups that had used the same liquid solutions as us. Later when we had all the information in hands we created graphs and tables to see our results, they are the ones that are below:

Appearance: 

 Day 1: The egg presents soft lines, the egg feels very soft and it is light.  The egg also presents an orange colour in some places, mostly top and bottom.

Day 2: The egg got both bigger and heavier, lost its orange colour, the lines got even more visible and still feels soft.

Day 3: The orange colour reappeared, got even bigger and heavier and now shows whiter spots.

Appearance:

Day 1: The egg had some whiter spots on top and bottom, presents a green spot, in some spots has an orange colour, also has soft line and feels soft.

Day 2: The whiter spots are still on the egg, the egg got both heavier and bigger, the green spot is gone, the orange spots became even more orange, the lines got even softer and harder to see, it feels soft and it is floating a little on the substance.

Day 3: Did not lose the whiter spots, got even larger and heavier, the lines almost disappeared and are really hard to see. 

Graph for Distilled Water:

Graph for Salty Water (20%):

We also took some pictures of how both our eggs looked after being opened, here are some of them followed by our observations:

Distilled Water:

Observations: After getting in contact with the sharp point the egg imidiately popped. Egg white looks like it was ripped to pieces, it also looks as if it were dissolved. There is a lot of water inside the egg. Egg yolk was not affected and still had its normal texture.

Salty Water (20%):

Observation:  Egg popped after coming in contact with the sharp point or instrument.Egg Yolk grew in size, egg white also looks as if it were dissolved. The egg yolk feels as if it is more solid than  liquid or as it is before.
 Fun picture of our group working:

Working hard to finish all the required steps on time, write results down and share them with each other!

Evaluating Team Work:

In my group everyone worked very hard and did all of their jobs. We distributed the tasks and did the observations and the appearances all together. It was a lot of fun working in this group because no one did more work than anyone else. We also always kept focus and did not fall into temptation of talking about other things. Once we were done we talked about each other’s ideas for the table and checked results. It was a great success and we did not encounter any difficulties.

What I learned + Diffusion and Osmosis in living things:

This experiment really helped me understand what diffusion, facilitated diffusion and osmosis are, how they work and what they are. An example of diffusion in a living thing is of the oxygen and carbon dioxide in our lungs and capillaries. When we breath in we bring oxygen into our lungs, this oxygen soon starts diffusing into the capillaries and so does the carbon dioxide, but on the opposite direction. We then breathe out the carbon dioxide. This happens every time we breathe in and out. I found it very interesting because I never saw the whole process of breathing in a so complex and detailed way and this example also helped me learn and understand the process of diffusion better.

Summary:

Our group started off by writing predictions, we chose to work with Distilled water and salty water (20%). We thought the Distilled water would increase the egg, since it is pure water, which no minerals in it, so the process of osmosis will happen faster. It sure did! Our prediction was indeed supported by our data, first of all the volume of water on the cup decreased rapidly and in great number. This shows that the amount of water inside the egg increased, both the circumference and the mass also did. The circumference increased due to the fact that the egg got wider because of the amount of water inside. The same reason goes for the mass, the water inside the egg made it heavier.  Some things that could have changed the results were the facts that first, some water spilled and second the tip of the sting to measure the circumference was ripping apart and could affect the measure with the ruler. A way to make sure this does not happen is use a different and new sting everyday and for the water be careful or even add a millimeter to the amount of water inside the beaker, which would not be precise either, but could be a way to fix it.

For Salty water we had the prediction that because of the amount of salt in the water the egg would lose water, but this time we were wrong, the egg increased in size, the volume in the cup decreased and both the circumference and the mass of the egg increased, we were surprised but came to a conclusion of why our predictions were not right. The water concentration has to be balanced between both sides, inside and outside the cell (in this case the egg), we would think that since the salt level was big inside the water, the water inside the egg would go to the cup, but it was actually the opposite situation. This happened because there were more solutes inside of the egg so the water went inside the egg instead of leaving it. What we could change would be the same things as for the first one. 

Concluding:
This experiment really helped me understand all that we have been learning in science class since we started our subject of cells. I also enjoyed working in this experiment because it was fun and different from anything you would expect to do in a lab. I really loved it and would adore doing it all over again, but this time with different liquid solutions. So, if you are having trouble understanding Diffusion, Facilitated Diffusion and specially osmosis you should ask your teacher to do this experiment in class, hoped you have enjoyed this blog post, see you soon!

Why am I, the DNA important inside a cell?

In this week´s science class we were divided into three groups of several people, after this each of us were given a organelle to represent inside the cell, for example, I got to be the DNA of a cell for one short day. After we were each given a role to play, all the groups were put into the same complicated situation: All the organelles were inside a boat and due to “overweight” the boat captain based on ours one minute speeches had to decide who would be through out of the boat and who would stay.

Since I was given the DNA, I first decided to do some research about it and which other organelles it “worked with”. I found out many useful information, read it all and put the main and most important points into my speech, which follows:

I am important inside the cell since I contain all the genetic information, in other words when two cells reproduce the DNA molecule divides and the new cell will have a mixture of both DNA´s. I, the DNA define “who” the cell is, it´s genetic code, for instance: colour, size, format or shape and others. So basically the DNA is what makes the cell what it is. The genetic information made by me is transported all over the cell by the RNA. I also command the protein production and the RNA who transports information to the Ribosome, who is the producer of proteins and only produces the protein according to the information sent by me.