Tuning Fork and Palm Pipe Lab

         Last week we used palm pipes to give us a sense of how woodwind instruments work. In order to produce a musical note, we would hit one end of the open pipe with our palm. Each pipe created a different sound due to their size. With a woodwind instrument, the fundamental frequency is 1/4. We also learned that because the palm pipe had one end closed when the sound wave was produced that there can only be an odd number of harmonics. The pipe that I was given (#9) produced a much lower note than those of my table mates because it was much larger than theirs. The larger the pal pipe, the lower the sound. This occurs because a longer pipe increases the frequency of the wave, while the shorter pipes have a much lower frequency.
          We then struck tuning forks and recorded the sound made with a microphone that was plugged into our lab quests. Our screen showed us a wide variety of frequencies, however the highest frequency was the note that was produced.


Once we recorded the sound waved produced by our tuning fork, our lab quest screen gave us this:

We then clicked "analysis"; "advanced"; "FFR" and finally "sound pressure", giving us a graph like this:

(photos taken by Megan Grealish)

Light & Optics in the Real World

The picture below shows me holding a mirror in front of another mirror. This created a never ending virtual image of me holding up a mirror.

In order to understand how a mirror works, you must also understand the laws and principles of light. When a light hits a surface, it bounces off of that surface at a certain angle. The angle that the light hits the surface, or the angle of incidence, will determine how the light bounces off. Objects like prisms scatter a beam of light and show the entire array of waves that are in the single beam of light (Dark Side of the Moon). However a mirror does not alter the incoming beams of light, instead the light rays bounce back. The image from a flat mirror is a virtual image because it cannot be focused, and the rays are not coming out at straight lines. The rays hit our eyes and enable us to see our reflection, however it is not really there. 

Physics Standard 6.1

Standard 6.1 Question: How is electricity generated by moving magnetic fields? 

In order to generate electricuty, we need electrons to move. Without moving charges electricity will never be created. Usually this is created by a voltage source, a set of wires which creates the current, and obviously a resistor. Examples of resistors that are common in our everyday lives would be things like lightbulbs. In our lab, the moving magnets push the charges- essentially the magnet acted as the voltage source. Because the charges were being pushed, we had the potential to create electricity because we were moving the electrons. This kinetic energy from the magnet turns into electric potential energy, and is then transferred through the wires which create the current and then into the resistor which gives off the light.

Example: Water Wave Generators

-Energy output is determined by wave length, height and speed
-Kinetic Energy generated from waves turns into "Ue"
-Ue goes through wires which transfer the current to wherever the energy is needed

Lemon Battery Lab

Link Regarding iPad Batteries

http://www.pcworld.com/article/2018970/ipad-family-aces-battery-tests-while-android-tablets-lag.html

Overview:

Over the course of this week, I learned about electrostatics (the movement of electrons) and voltage (the measurement of electricity). We had an assignment that asked us to place a comb next to a thin stream of water. We had previously used the comb to comb our hair, which gave it a charge. The comb forced the water to move closer to it, proving that we had charged the comb.

-After the Lemon Battery Lab I got a true feeling for what voltage is. It's simply Electric Potential Energy. Also, when solving equations regarding electrostatics, voltage = height. Voltage is essentially building up this big mountain of energy (which is why it is similar to height), which then gets transfered into other things. An example would be the "mountain of energy" that you built up and transfered when you combed your hair and put it up near the stream of water.

-This analogy on voltage can be applied to iPad batteries too. The newer iPads have much larger batteries, making them more powerful and giving them a longer lifespan. What the larger battery is doing is just creating a larger "mountain of energy" that is used to power the various apps and programs that are running on your iPad. 

Projectie Motion

Brief Description of the Lab:
In this lab we were given the task to find out what the true definition of a projectile is. To figure this out, we went down to the basketball courts and filmed the flight path of a basketball after it had been shot. We were able to find out the acceleration and velocity of the ball in the x and y dimensions.

Vy:

This graph gives us all of the information we need to find the y component of the basketball being thrown. The parabolic shaped graph (top graph) shows us the y position over time, ultimately giving us the value of the slope of the line which is velocity. When looking at the graph you can tell that the slope is not constant, meaning the velocity is also not constant which gives us the idea that the basketball is accelerating.

Vx:

This graph below shows us the x position over the period of time that was taken to record the basketball shot. The slope of this graph is represented by the change in position over the change of time. Unlike the Vy of the basketball, this is constant. THis means that there is no acceleration in the horizontal dimension and that it is constant. 

Photo of my group's whiteboard:

2-D Forces and Circular Motion

1)      To analyze forces in 2D one must find the magnitude (or size) of the x and y intercepts. The x and y intercepts, when in the second dimension, are called Force X and Force Y. In order to find the values of fx and fy you use sin, cos, and tan.

2)      Forces cause objects to move in a circle by pulling them in with a gravitational force. During our hover disc lab, we exerted a tension force (similar to the gravitational force of the earth on the moon), on the hover disc. We learned that the hover disc is being pulled into us but is also constantly accelerating, which enables it to move around us in a circle. A real life example of this would be the International Space Station and its orbit around Earth: Because the tangential velocity of the space station is so great, it does not matter whether or not the space station is in a constant free fall. The station never comes crashing down into the is because we simply keep missing it. There is no air resistance in space as well,  disabling space station's velocity from slowing down.

http://commons.wikimedia.org/wiki/File:ISS_after_STS-124_06_2008.jpg

3)      To be in orbit means that a small object is in a constant circular motion around a much greater object. The larger object is exerting, or pulling,  a gravitational force on the smaller object, which is in a constant free fall (as we learned in the video).  Satellittes orbit Earth in the exact same way. Satellittes are in a constant free fall around the Earth- their velocity is so great that they constantly "miss" the Earth, just as planets do to the Sun.

Newtons 3rd law

Purpose:
The purpose of the Fan Cart Lab was to measure the increase and decrease of acceleration produced by the fan cart on a track that had little to no friction. The force that was produced from the fan cart remained constant,  even though each test had different accelerations. During each of the tests, we increased the mass of the fan cart to see if there would be a difference in acceleration or force. Meanwhile, all of this was being recorded on the range finders.





Data:

After reviewing the data of the lab, we know that the relationship between mass & acceleration is indirect. We also learned a new equation: force= (mass)(acceleration). Finally, we cam to the conclusion that an object will remain in motion unless an outside force is acting upon it, an example in this lab would be someone catching the cart and pushing it. 

Real World Connection:

The connection to the real world with this lab involves my cat, Simba. When he runs around my house, he tends to slide due to the stone floors. The absence of friction makes him slide and smack himself into the side of our walls. The wall and Simba both experience the same amount of force, but the wall is much more massive and experiences no acceleration after the crash, while he lays there stunned.