Week 33 Reflection

This week in physics we continued to experiment more with the magnetic sphere and we were able to experience how the energy flowed through us when the class all linked together. We then moved on and focused mostly on creating the styrofoam speakers in class and completing our presentations for the upcoming demonstration in class next week of our project. This was our main activity for the week. 

Before starting our styrofoam plate speaker, we had to do some research to learn how actual speakers work and figure out the physics behind them. I learned that in order to translate an electrical signal into an article sound, speakers have to contain both a permanent and electromagnetic magnet. The electromagnet is a metal coil that creates a magnetic field when an electric current flows through it. This is why we had to coil the red wire around the paper for our styrofoam speaker. 

The permanent magnet is fixed in position, but the electromagnet is mobile. When pulses of electricity pass through the coil, the direction of its magnetic field is rapidly changed. This causes it to attract and repel from the permanent magnet, resulting in a back and forth vibration. The electromagnetic coil is connected to a material such as plastic (styrofoam for us), which amplifies these vibrations. The amplification pumps sound waves into the surrounding air and towards your hears, allowing you to hear the sound. 

Our styrofoam plate speaker has all the same parts that act the same way, but they are made of different materials. I'll let you know how it goes next week! :)

Week 32 Reflection

This week in physics we began looking at static electricity, air particles, and electrons. We conducted an experiment in which we put tape on top of each other, petted it, and then ripped the two pieces apart. We then took the tape and put it next to different materials and observed if they attracted or repelled. From this experiment we learned that only electrons, or negatively charged particles, can move from object to object. Protons, positively charged particles, stay in place. We then had a demonstration to  with boys and girls in the class to portray the different pieces of tape and their charge. The guys were positive and the girls were negative. They were to show of a piece of tape could be negative, positive, and neutral. I didn't know that it mattered where the electrons were in a object and that it affected the charge of the whole object. 

In addition to the tap experiment, we were also able to observe the magnetic ball that gives off static electricity. We jest started by putting bunny fur on the bulb, which resulted in the hair standing up. Then we had someone put their hands on the bulb and observed her hair begin to stand up in the front. I was then able to touch Emily and was shocked due to the transferred electrons. A group of students then formed a line holding hands and they could feel the energy of the electron transfer going through their body. I hope that we can experiment more with this next week. 

We also learned a little bit about conductors and insulators. Conductors allow energy to pass through them and are typically made of metal. However, insulators don't allow electricity to pass through them so efficiently. 

Sorry it's kind of sort Maggie, but we find cover that much this week :) 

Week 31 Reflection

This week in physics we began our new unit, which deals with light waves. We began by turning off the lights in the room and observing a laser going through different medium, including glass and water. We observed that the light of the laser can be reflected or refracted. This means that the light beam can remain straight or become bent due to how it reacts with the surface. For example, when he laser was shown through a glass of water, the laser refracted and bent when going through the water. 

We also looked at the electromagnetic system, it's different waves, and the visible color range. I learned that an electromagnetic wave is a transverse wave that does not require a medium to travel. The electromagnetic spectrum from greatest to least wavelength is radio waves, microwaves, infrared waves, visible light, ultraviolet light, X-rays, and gamma rays. As you follow the spectrum from left to right, the wavelength distance decreases, the frequency increases, and the energy increases. With the increased energy, the speed of the waves also increases. The visible color range from left to right is red, orange, yellow, green, blue, and violet. Humans see these colors because of three cells in our eyes that controls the colors of red, green, and blue. These colors mix to form other colors of the visible color range. 

In addition, we also learned about cancer and how it can be caused by light rays. The smaller the light wave, the more energy the wave has. The greater the energy, the greater the capability of the light wave to penetrate your skin and cells. If the light wave does penetrate a cell, it can damage the cell's DNA and cause the damaged cell to multiply other damaged cells. These defective cells can clump together and can form tumors in the body. When doctors attempt to kill the cancer, they have to kill the defective cells without damaging the healthy ones, which has proved to be very difficult. 

Week 30 Reflection

This week in physics we continued to study sound waves and began to discover the speed of sound. We held an experiment in which a person clapped two wooden blocks together and walked further and further away. The point where the blocks were apart from each other when you heard the clap of the blocks was the sweet spot. The time it takes for the hitting of the blocks and the clap is equal to the amount of time it takes to reach your ears. We found out that it takes .25 seconds to reach our ears from a distance of 83 meters. The actual speed of like is 300,000,000 meters per second, or 186,000 miles per second. 

In addition to our experiment, we also learned that the speed of different sounds is affected by the medium and temperature. A mechanical wave is a wave that needs a medium to travel. We experienced this with the Ruben's Tube, which was a tube that you could like that would show the sound of music moving through the fire in a wave. It was cool to see how different songs and beats went through the fire. It's nice to actually see things happening than talking about things you haven't visually seen. 

On Wednesday we began looking at a worksheet in preparation for our assessment that includes equations regarding wavelength, frequency, velocity, and the period. Velocity equals wavelength times the frequency and and the frequency equals one divided by the period. Also, the period and frequency are reciprocals. The greater the wavelength the less the frequency. The highest pitch is the wave that has the highest frequency and the lowest pitch is the wave that has the lowest frequency. Because I wasn't in class on Friday, I will take my assessment tomorrow on this material. 

Week 29 Reflection

This week in physics we began looking at oscillating systems, their energy, and their different parts. We started by looking at weights on a spring that would continually bob up and down when the weight was released. We discovered that the oscillating system with the weight was a mixture of all three types of energy transfer, including elastic, kinetic, and gravitational. At the minimum, the energy was all elastic and at the maximum, it was all gravitational. The stages in between we're a mixture of the three different energies (see picture below). The energy transferred up and down, which was in the same direction as the object. This classifies it as a longitudinal wave.

This lab led to our next activity, which was experimenting with a slinky stretched across the room and creating different types of waves. A longitudinal wave is a wave in which the energy get transferred on the same direction of the object. An example of this is the spring when we pulled a section back and let it go. The compression of the slinky was in the same direction. The compression is when the coils are close together and rarefraction is when the coils are not compressed and at at a normal position. You can see the compressed coils move through the slinky because of this difference.

A transverse wave is when a system has energy transfer that is perpendicular goth motion of an object. This creates crests and droughts in the waves. An example of a transverse wave is an actual wave in the water. The waves move up and down but the energy is in a horizontal direction.

In addition to learning about these two different waves, we also learned terms that have to do with them.
Amplitude- the maximum displacement from a zero point.
Wavelength- the distance between two successive points on a wave
Period- the time for one full cycle
Frequency- how many waves per second