Palm Pipe Lab

In this lab, we determined the musical notes that our palm pipes produced. First, we measured the length and diameter of our palm pipes and converted our measurements from cm to m. Second, we solved for wavelength: L=1/4(wavelength) - 1/4(diameter). After finding wavelength we then solved for frequency: V=(wavelength)(frequency). After finding our "peak" frequency, we then plugged it in to Wolfram Alpha to help us determine our musical note.

Rainbows

The photo above is a photo I took of a rainbow outside of my house. I chose this picture because we are learning about light and refraction. A rainbow is formed when a light ray passes through a spherical water droplet and is reflected and refracted. This is like the car and the sand diagram. The light enters the water droplet at almost an angle and the different rays of color change speeds through the droplet. The light that enters is then reflected off the opposite side of the droplet and changes the direction of the light. When the light leaves the water droplet, the light ray is dispersed and the different color rays (ROYGBIV) are refracted down toward earth.

Magnetism

Magnetic fields can create electricity/ currents. When you move a wire though a magnetic field, it creates a current. This can be related to the hand generator we used in class. To create a current, you not only need a magnet and a coil of wire, but also movement. When you crank the handle, the magnet is moved in and out the wire, and this creates a current, because the electrons in the wire interact with the poles of the magnet. When current flows, the wire becomes magnetic. When the current is revered, the polarity of the magnet switches. In other words, the North and South orientation switches. The higher the electric current and the greater number of loops in the wire contribute to a stronger the magnetic field.

iPad & Lemon Battery

In an iPod, computer, iPad, and many more things there is a battery called an ion lithium battery. Each cell of a lithium- ion battery produces about 3.7 volts, while the average AA battery produces 1.5 volts. Lithium-ion batteries are popular because they have a number of important advantages over competing technologies.
1) They're generally much lighter than other types of rechargeable batteries of the same size. The electrodes of a lithium-ion battery are made of lightweight lithium and carbon. Lithium is also a highly reactive element, meaning that a lot of energy can be stored in its atomic bonds
2) They hold their charge. A lithium-ion battery pack loses only about 5 percent of its charge per month, compared to a 20 percent loss per month for NiMH batteries.
3)They have no memory effect, which means that you do not have to completely discharge them before recharging, as with some other battery chemistries.
4)Lithium-ion batteries can handle hundreds of charge/discharge cycles.
(http://electronics.howstuffworks.com/everyday-tech/lithium-ion-battery.htm)

In class we made our own battery by using a lemon, a penny, and a nail.  In class we discussed voltage, which is a field surrounded a charged object. The lemon acted as a battery, and the nail and the wires as charges. In class we used these to see how much voltage we could make and to see if we could make a little light go on. 

Projectile Motion

Big Questions: "What is a projectile?" and "What is the general path of motion? Why?" 

In this lab, we used the Vernier Video Physics app to analyze the projectile motion of a basketball shot into the air. One of my classmates took a video of me shooting a basketball and I used this app  to make a motion map on the video and then it produced X vs. Y charts. The X is the motion in the horizontal direction and the Y is the motion in the vertical direction. A projectile is an object propelled by an external force. The general path of motion of a projectile is a parabolic arc.

For the motion in the X direction:
-Velocity is constant
-Acceleration is always 0
-Never speeds up, slows down or stops
The two equations we derived were:
- Vx=Vxi
-Xf=Vxt+xi

For motion in the Y direction:
-Velocity is changing
-Acceleration is always -10m/s
The two equations we derived were:
-Vy=(-10m/s)t+Viy
-y=1/2(-10m/s)t^+Viyt+yi

Hover Disk- Centripetal Force

Big Questions: "How do forces cause objects to move in circles?" "What does it mean to be in orbit? How do satellites orbit planets and how do planets orbit the Sun?"

To answer these questions we used a hover disc attached to a string. We held the string and spun in a circle--imitating the gravitational pull of the moon orbiting the Earth. In order to analyze forces in two directions, two vectors need to be involved. Vectors need speed and direction. When objects move in a circle, their velocities want them to keep moving in a straight line. However normal forces from seats and doors cause the direction of our velocity to change and causes us to go in a circle. In this specific lab, there is a tension force between the person and the disk--the string. This tension force's direction is inward towards the person. When an object is shot into space, gravity pulls the object down at great speeds. The object is basically falling toward Earth, but misses because the Earth is also rotating. This is how satellites and space stations orbit Earth. The planets orbit the sun because of sun's gravitational force. Since there are no other forces in space, the planets only have the sun's gravitational field. The Earth has a velocity that is perpendicular to the Sun's gravitational pull. We then made an interaction between the person, the disk and the Earth. Between the person and the Earth, there is gravitational and normal force. Between the disk and the Earth there are normal, gravitational and friction forces.There is also a tension force between the person and the disk.