Unit Six was a whole section on energy and electricity. We got to work with light bulbs and learned why a lot of things happened to us like our hair standing up and how lightning worked. Hopefully, this reflection will help with the many difficult concepts we discussed in the past few weeks.
Energy and Electricity:
The essential question was: How does a battery, wires, and light bulb fit together to make the light bulb light up? This was a lab in which we were given a battery and some other objects and we were asked to light a bulb with no knowledge of what to do. Eventually, we got it. Our design looked like the picture on the right. It lit up with the wire like that because it completed a full circuit.- Direct contact
- Friction in which they steal electrons from each other
- Induction which is charge without contact
- A good example of induction is lightning
We also learned about how the outlets in our houses work. They only work because electricity flows in a circuit which makes appliances light up. There are several parts in what makes outlets work: ground wires are wires that complete a direct path to the ground when it takes the oath of least resistance.
It was also interesting to learn how much the energy we use everyday cost. Appliances like the ones below were pretty cool to see.
Charges:
Next we learned about charges and how they affect us and the objects that surround us. Some of the essential question were: why does our hair stand up after putting on a sweater or why does our hair stand up when we rub a balloon on our heads.
I learned that there are three types of charges: positive, negative, and neutral. When it is positive, there are more protons in the system than electrons, when it is negatively charged it is the opposite. But when we say neutral charge, we mean that there is an equal amount of protons and electrons.
Because I stated that there are positive and negatively charged things, there has to be a way in which they become this way.
Polarization:
In this unit, we learned about how neutral objects become polarized. Knowing that there are three different types of charges, polarization is the explanation for why they are charged and what makes them charged. Polarization has to do with two objects being polar. Polarization can be found in conductors and insulators because a conductor lets charges move through the object and insulators stop charges from moving. Polarization is basically the separation of charges. A polarized object is still neutral because the charges are only separating; the electron count is not changing. Coulomb’s law relates to polarization because it is the force between any two charges and is inversely proportional to distance. This law is written like so:
An example of this is when someone puts plastic wrap on a metal bowl. When the plastic wrap is charged by friction when brought near the bowl, the bowl is polarized. The positive charges in the bowl move close to the negative plastic wrap an the negative charges move away.
Lastly, in this unit we discovered two different types of circuits. We looked at series and parallel circuits.
With this law, when there is a large distance there is a smaller force and when there is a small distance there is a larger force.
Then the distance between the opposite attractive charges is smaller than the distance between the repelling.
Another problem that is extremely important in this unit is the balloon problem. The balloon rubbing on your head and then being placed on the wall is a big problem because it describes many aspects of electricity and charges.
First, the balloon takes electrons from your hair. It is charged by friction because they are directly in contact. Now, this means that the balloon is negatively charged. When it is placed on the wall, the neutral wall polarizes. Positive charges move closer to the baloon. Negative charges move away because opposites attract and like charges repel. The distance between the opposite attractive charges is less than the distance between the like repulsive charges because of Coulomb's law as I described earlier. Because the attractive force is larger, the balloon sticks to the wall.
Electric Fields:
An electric field is the area around a charge that can push or pull another charge. It is basically the direction that the positive particle goes. The arrows around an electric field also show the strength of the electric field and also the direction. The closer the lines are the stronger electric field and the further apart they are, the weaker the field is.
Electric shielding relates to electric fields and happens when something is placed in a metal container and the charges will distribute evenly no matter where they are.
To find the strength of an electric force, we use the equation E=force/charge or E=f/q because the charge is per coulomb.
Voltage:
Voltage has to do with a charge difference. There is something called electro-motive force which is when there is a bigger charge difference/bigger voltage, the bigger force electrons will feel. Another word we use to associate potential difference is voltage. It is derived from potential energy because there is a potential energy between two points. In other words, it is a measure of how much energy we can get out of one coulomb of charge. The change in potential energy is the same as the kinetic energy. The formula for voltage is the potential energy divided by each coulomb of charge. V=pe/q Voltage is measured in Volts.
To put this formula into use, here is an example: If a 3 Coulomb charge has 12 Joules of potential energy at some point in space, what is the value of the electric potential?
V=PE/q
V=12/3
V= 4V
Current:
Then we learned about current, how to measure it, and the different types of current there are.
Current is the flow of electricity that is caused by movement of particles that is measured in amperes (I). The two types of current there are are:
- Direct current which is when the flowing of charges in one direction. Some devices that have this type of current are: batteries and laptops.
- Alternating current is when electrons in the current are moving in opposite directions at some amount of time. For example, a household current.
In order to convert these current we use diodes which are devices to convert ac-->dc
To complete a circuit, there must be current. Current happens when there is change in voltage. There is an example in class about birds sitting on wires. The reason why birds aren’t harmed when sitting on a power line wire is because If a bird was standing on only one wire, they did not complete a circuit because they aren’t touching the ground and they aren’t touching the two wires at the same time. This means there’s no current meaning that there is no electric potential difference. But if it were flying and both of its wings happened to touch each wire, there would be a complete circuit which would harm a bird.
Resistance:
Resistance is the property of a material that resists electric current. When resistance is high, current is low and vice versa. It is measured in Ohm's and can be written with the letter R to represent it. The resistance of objects like wires depends on the thickness and length. The thicker, the shorter, and the better conductor material, and the colder the wire is, the wire is the less resistance there will be meaning there will be more current. But light bulb companies should make filaments thinner and longer to have bulbs that have a smaller current but bigger resistance so they would last longer. Earlier I mentioned that resistance was measured in Ohms. Ohm's law states that current in a circuit is directly proportional to voltage and is inversely proportional to resistance of the circuit.
The law is written like so: current = voltage/resistance
The law in measurements is: amps = volts /ohms
The law is written like so: current = voltage/resistance
The law in measurements is: amps = volts /ohms
Electric Power:
Electric power is the rate in which electric energy is converted into another form. For example, heat and light because they are different forms of electricity. Power is measured with direct proportionality between current and voltage.
The equation for power is: power=I*V
The measurements for this equation: watts=amperes*volts
There is also a relationship with power and energy and that is just power=energy/time
Circuits:
Lastly, in this unit we discovered two different types of circuits. We looked at series and parallel circuits.
Series Circuits:
In a series circuit, all of the things that are plugged in are following one path in which they are all connected. If you remove one things, the rest of the things go out. In a series circuit, resistance is added together, voltage also adds, but the current remains the same.
Parallel Circuits:
In parallel circuits, two or more bulb are connected by different wires but to the same wire source. They eventually connect also but they are not in a row the way a series circuit is. The resistance is cut in half, voltage remains the same, but the current is added together.
Difficulty:
This unit was probably the hardest unit so far for me. Probably because there was a lot more materials, less blog posts to help me, and a change in teaching styles as Ms. Lawrence left. I found that memorizing all the big problems and having to remember all the different equations in order to solve a problem right was hard for me.
I overcame these difficulties by staying patient and kept doing my homework everyday. I came into conference period about two or three times to seek help also. The lightbulb clicked just by doing more practice problems, searching a couple of concepts on Google, and asking questions.
Problem-Solving Skills, Effort, and Learning:
Effort in class: I don't think I was able to contribute in class as I have in the past because this unit was really difficult and I usually learn better by intaking the information first and then giving it back verbally but it took me a while to understand the concepts. Also, there was one time when I had to give myself a 0/3 on homework because I wasn't able to have it completed and that has never happened before.
Homework: I learned a lot from doing the homework problems because in this unit the outside of class assignments were what tied everything together for me. Although I missed one assignment, it happened because I had a lot of work to do. I was even able to complete this blog post even though my computer broke a couple of days ago, so I feel as though I maintained my homework throughout the unit.
Groupwork/Peers: This was a difficult unit to stay focused on because at times it got boring because I didn't understand what was going on but my effort in groupwork was still good and also I learned a lot from Paige and Abby when I didn't understand what was going on. I do think that my learning was affected because there are students in my section who are extremely distracting which caused me a lot of frustration this unit.
Goals:
For next unit, I plan on doing more research if I do not understand something and also reading the pages in the textbook for support. I stopped going in during my free period to ask questions and talk to my teacher but I might have to start that again depending on how this test goes for me tomorrow.
Connections:
Many of the connections that I saw outside of class were already put into Part A.
Podcast:
In this unit we did not do podcasts. Sorry!
This unit was probably the hardest unit so far for me. Probably because there was a lot more materials, less blog posts to help me, and a change in teaching styles as Ms. Lawrence left. I found that memorizing all the big problems and having to remember all the different equations in order to solve a problem right was hard for me.
I overcame these difficulties by staying patient and kept doing my homework everyday. I came into conference period about two or three times to seek help also. The lightbulb clicked just by doing more practice problems, searching a couple of concepts on Google, and asking questions.
Problem-Solving Skills, Effort, and Learning:
Effort in class: I don't think I was able to contribute in class as I have in the past because this unit was really difficult and I usually learn better by intaking the information first and then giving it back verbally but it took me a while to understand the concepts. Also, there was one time when I had to give myself a 0/3 on homework because I wasn't able to have it completed and that has never happened before.
Homework: I learned a lot from doing the homework problems because in this unit the outside of class assignments were what tied everything together for me. Although I missed one assignment, it happened because I had a lot of work to do. I was even able to complete this blog post even though my computer broke a couple of days ago, so I feel as though I maintained my homework throughout the unit.
Groupwork/Peers: This was a difficult unit to stay focused on because at times it got boring because I didn't understand what was going on but my effort in groupwork was still good and also I learned a lot from Paige and Abby when I didn't understand what was going on. I do think that my learning was affected because there are students in my section who are extremely distracting which caused me a lot of frustration this unit.
Goals:
For next unit, I plan on doing more research if I do not understand something and also reading the pages in the textbook for support. I stopped going in during my free period to ask questions and talk to my teacher but I might have to start that again depending on how this test goes for me tomorrow.
Connections:
Many of the connections that I saw outside of class were already put into Part A.
Podcast:
In this unit we did not do podcasts. Sorry!
