# linerider

### Physics of Linerider IV: Friction?

Friction in Line Rider Is there friction in Line Rider? Does it function as physics would expect? To test this, I set up a simple track: ![Page 6 1](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/09/page-6-1…) Basically, a slope with a flat part to start with and to end with. Let me show you something simple before further analysis: ![Page 6 2](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/09/page-6-2…) This is the x-position vs. time for the line rider on the first horizontal portion of the track (before he or she goes down the incline). This shows the rider…

### Physics of Linerider III: Air Resistance

There is no air resistance in line rider. Sorry to spoil the suspense. To test for the presence of an air resistance force, a track was created that let the rider fall. ![linerider air 1](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/09/linerider…) (note the markers on the side. These are used to keep track of how the origin is moving). Below is the y position of the rider as a function of time: ![linerider falling](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/09/linerider…) In this situation, the rider falls about 100 meters. A quadratic line is fit to the data…

### Physics of Linerider Part II: Scale

Scale of the Line Rider First, we assume that the line rider is on Earth and for low speeds will have a free-falling acceleration of 9.8 m/s2. Next, an arbitrary distance is selected. In this case the length of the sled is chosen to be 1 LU (Linerider Unit). ![line rider](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/09/line-ride…) The goal will be to put the linerider in a free fall (where air resistance should be able to be ignored) and determine his (it could be a she, it is difficult to tell) acceleration in LU/s2. Then we can determine the conversion factor from LU/s2 to…