Van de Graaff Explanation

The Van de Graaff is a generator with a belt that sends charges to the top on the metal globe. The Van de Graaff is positively charged.. It is positively charged because the band inside the glass tube takes electrons from the glass tube, making the glass positive, and the band with a negative charge. The Teflon Pulley has a higher polarity than the belt due to triboelectric series. If you put pie pans on the top of the metal globe, when you turn the generator on, the pie pans fly off. They fly off because they are positive as well as the Van de Graaff, so the two positive charges repel each other. The Teflon Pulley exchanges electrons with the band making the Van de Graaff a positive generator. The Teflon Pulley gathers up the negative charges. The belt sends charges to the Teflon Pulley because it exchanges electrons which makes the Teflon Pulley positive. This makes the metal globe positive.

Force Analysis Of Cardboard Chair!

This is our sort of free body diagram of our chair. The chair is in the middle, and there is a big arrow pointing down from the chair. When you sit down on the chair, the force is going down. The two legs have an upward force. In the picture, the top square is the back. The middle one, that looks like a checker board, is our seat. The two random boxes sticking out on the bottom of the picture is the two boxes that we have under our chair. There is a force going to the left and the right. There is a force of going on the back. Therefore, there is one on the opposite side. The correct vectors are the one's on the right. NOT THE LEFT.

We learned that all sides of the cardboard must have some type of support on them. It must all be even. We also learned that we must all show up to work on the chair to get the finished product done. We learned the different type of force vectors that are forced down onto the chair. We learned how to invent a chair!!!!

More Progress on Cardboard Chair!

 In the picture to the right, we are placing rows of cardboard into slits that we cut into the legs of our chairs to help support the weight of the seat.  

 In the picture above, we are rolling cardboard to place in between the legs of our chair to help support the weight.

 In this picture above, we are now placing our rolled cardboard in between the legs of the chair. This is to help the legs stay sturdy to be able to hold you up.

 In the picture above, we are all cutting slits into the legs of our chair so that we can place rows of cardboard in between them for support.

To the right, we are placing the seat, where your bottom will go, above the rows of cardboard slits we put into the legs.

This is also a picture of us placing cardboard into our slits above.

Lab Report of Spring and Rubber Band

1) Procedures :
  -gather all materials that are needed (rubber band, spring, weights, clips, timers, medal rod, paper, pen, and calculator)
  - place a little amount of weight onto the spring and measure the distance of how far it went down.
  -time the amount of time it took for a certain amount of oscillations (we did 15)
  - place more weight each time you do a new one
  - just continue to keep adding weight until you have enough data
  -be sure to right all you data done (such as the weight you put on and how far it went down)
  -place a little amount of weigh onto the rubber band and do the same thing for it as you did with the spring.
  -calculate the weight in grams into newtons.
  -graph displacement vs. force and also period vs. force.
  -calculate slope.
  -find the spring constant of the rubber band and the spring.
  -now the lab is done :)

2 and 3) Table Format and Analysis of Data:

 Above is our graph of displacement vs. force.

 Aboce is our graph of period vs. force

This is our set up above.

 Above is our data that we wrote down. The weight we put down and the oscillations and time.

 Above its continued on the rubber band.

 Above again is our set up.

 Above is the rubber band with weight on it.

Above is the spring and rubber band in action with weight on them.

Above is our calculations of our Spring Constant. The bottom work shown is the rubber band's spring constant.
4) I learned that a spring bounces more slowly with more weight than a rubber band does. The more bouncy an object is the more it will bounce than an object that is more stiff. An error that happened with us was we timed our oscillations wrong the first time, so therefore our spring constant would be wrong and our graphs would be wrong too. An application that is applied to this lab would be a bungee jump cord. The more bouncy it is the more trips you will take up and down. Also, there will be more time. If the cord is stiff like a rubber band, then you won't have much time on the cord, and you wont bounce as much.

Cardboard Chair Project!

Here are the pictures of my group and I beginning to build our cardboard project.

*In the pictures below, we are gathering our cardboard we will be using, the glue, and the scissors we will also be using. We gathered the cardboard from Kendall's garage and the glue and scissors from her cabinets in her house.

*The pictures below are of my group and I beginning to cut the sides (legs) of the chair and the seat. We measured a distance of the seat and the length with a measuring tape. (sorry...one of them is sideways and I don't know how to change it) sorry :)

*The pictures below are of us beginning to place our chair together. We are placing the legs and the seat together to form the bottom of the chair.  We have a front view of the chair and we also have a side view of the chair.

Inertia Trick

The purpose of this experiment is to show a trick using inertia. The materials needed for the trick I chose, are a coin, a card (like playing cards. solitare cards), and a video camera. What you do is place the card on your index finger with the coin centered in the middle of the card, while it is on your finger. You must balance it in order for it to stay put. Then, once it is balanced, "thump" the card with your fingers. (In other words, flick the card). Once you have done this, and you did it correctly, the coin should stay put on your index finger. If it did, then your inertia trick turned out correctly and you just proved inertia! Whoohoo!
Here is the video of me showing this Inertia Trick:

Friction Lab Report

Procedures: (1)
-gather all materials (small block of wood and a larger block of wood)
-place sand paper on one side of the small block of wood
-weigh the small block of wood
-place the block with the sand paper on the side onto the larger block of wood and angle the wood until the wood falls off.
-measure the angle of where the wood fell off.
-do the same for the block of wood that does not have the sand paper
-draw a free body diagram
-place all of you information(angles) onto the diagram
-use cosine and sin to get the vectors
-use cosine and sin for both of the different angles
-now draw two more free body diagrams.
-place the new information onto it.
-now use the formula U=Ff/Fn
-this will give you the new vectors for friction. (use this formula for both diagrams)
-Now...you are finished :)

2)THIS IS MY TABLE!
Go to this website :)
https://docs.google.com/spreadsheet/ccc?key=0AuLTcm7cYv6vdFd6X21wTWJaVjE2Tk5iNFMwbDJDOGc&hl=en_US
3)

Above are our calculations.Below is the smooth side falling off the ramp. 

(4) Conclusions
In conclusion, I learned how to find the friction of an object just by determining the angle of which it fell off of something, and then plugging it into various forms of equation. If we would have plugged either the opposite or hypotenuse into the wrong place, then our answers would have been wrong. This meaning that the vectors that we got would have been wrong, and friction would be wrong. You have to pay close attention to what information goes where. You can use this type of principle to determine the friction of speed a car was going before it wrecked. The cops could use this information to determine if the speed was legal or illegal. So therefore, the friction experiment is very useful.