## Monday, December 6, 2010

### Monday, December 6th: Skateboard Problem

Today, in class, I began working on the skateboard problem. For the skateboard problem, the first part is to design a skate park for the skater to skate on. After a few minutes of designing, I designed a skate park like this:

Afterwards, I had to answer a few questions about the skater/skatepark. Here are my questions and answers:

a) Draw a picture of your track.

(shown above.)

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Place the skateboarder on the track and observe the motion. You can investigate further by changing the skate or you can scroll down and adjust the fiction. Choose two different situations from the simulation that you can analyze and then share with the class.

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1. My first situation is on Earth, with the PhET skater. The track is my original track shown above, and the friction is none. I observed that the skater keeps on going at a consistent speed and it pauses for the same amount of time when it reaches the ends of the track every single time.

2. My second situation was using a bulldog on the Moon. The track is still my original track, but the friction is medium. I observed that the bulldog wasn't able to move as fast; in fact it couldn't even go through the loop because of the friction. Things on the moon are supposed to be lighter, so friction can really slow someone down.

b) Describe or draw your chosen initial and final states

initial final

c) Include your choice of a systems

My choice of the system is the Earth and the skater.

d) Create three different representations (i.e. picture, bar chart, force/motion diagrams, number statement, graphs, etc) to demonstrate the changes that occurred during the process.

40J + 20J = 20J + 40J

e) Is the skateboarding situation realistic in terms of the physics and energy?
Yes, because the more friction there is, the harder it is to move in real life. Not any of the things programmed into this game have violated the laws of physics.

That is about all we did in class today. If this wasn't finished in class, it was finished for homework.

- J.L.