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. 

Impulse Lab

Purpose:
In this lab we a cart with metal bands attached to its end, into the left end of the track. The metal bands were used to "slow down time". We pushed the red car towards the left side of the track. Because it had a metal band on the end of it, it bounced back. On the computer the graphs were able to tell us the velocity before and after the collision.


Data:
                        Impulse remains constant in a collision      

*Impulse: J=F (force) X T (time)

*Force and time are inversely proportional

*Impulse = area of force vs. times graph

Connection to the Real World:

The first connection I made to the real world would be in any play in water polo. When you are passed the ball, you need to catch the ball with a finess that essentially reduces the force of the pass hitting your hand. By doing this you enable the velocity of the ball to decrease with ease, just like the metal rings on the carts in the lab.

Collisions Lab

In class: 

This week in the collisions lab we were given two carts (one red and one blue), a computer, a track and two motion sensors that were connected to a labquest. We put the two carts on the track and sent them towards each other in two different types of collisions, one elastic and one inelastic. The sensors would send out sonar waves to the carts, and would be able to tell how far away the cart was from the senor at any given second. In the elastic collision, both of the springs on the carts were facing each other, in the inelastic collision, we have the velcro sides of the carts collide with one another.

Data:

MOMENTUM IS CONSERVED

P(total before)= P(total) after

m + v x m x v = m + v x m+ v

The two right columns on the data table explain to us what this equation above really means. As you can see, the amount of momentum decreases, meaning it is conserved.

Connection to the Real World

Any collision from the real world can be applied to this, one that comes to mind is bowling and more specifically when the bowling ball strikes the pins. The collision between the ball and the pins is inelastic. When the two hit one another, the momentum is conserved. This is exactly the same as the inelastic collision we tested during class.

Rubber Band Cart Launcher Lab

In Class:
The purpose of this lab was to calculate and find out the relationship between energy and velocity. In this lab we put a .38 kg glider on an air track, and measured its velocity when it passed through a photogate sensor we had set up about a foot down the track. We pulled the glider back, stretching a rubber band at .01 to .05 m and measured the velocity when the glider was released during each test.  After the testing was completed, we graphed the data and came up with an equation explaining the reasoning behind our graph and its slope: E=1/2mv^2. This equation tells us that the energy of the glider is equal to half of its mass multiplied by the velocity of the glider squared.

Data:

The velocity and energy have a direct relationship:

X and Y coordinates of the graph below

Graph showing the trend and relationship between Energy and the average velocity squared

Connection:
A connection that we can make to the real world is eerily similar to our previous labs connection. Last week we figured out how to store energy in a rubber band, the connection being a bow. However, this week we basically tested the other part of a bow, the arrow. When we pulled the cart backwards, stretching the rubber band back, we were loading up the rubber band with energy. The further we pulled the rubber band back, more energy was stored and the glider would move faster. This is similar to a bow and arrow because the more you pull the string back, the faster the arrow will go- just like the glider and rubber band.