RipStik in physical science: accelerated linear motion

In a previous article I shared the use of a RipStik in SC 130 Physical Science to demonstrate linear unaccelerated motion. The ability to generate a relatively constant velocity by swizzling at a constant rate on level ground was useful to that demonstration. In this demonstration I accelerated the RipStik from rest over a distance of 9.2 meters using columns that were 4.1 meters apart. Measuring the time as I passed each column permitted a calculation of the average speed between each column.

A student captured the image above. The external light and lack of a flash meant that the image had to be processed using a retinex filter in GIMP to lighten the foreground relative to the background. My watch can be seen in my right hand, I used the chronograph feature to capture the split times.


This demonstration required that I accelerate, which meant swizzling faster and with more force than the previous constant rate swizzle. This required more skill than last week. The time and distance data gathered was recorded on the board back inside the classroom. The velocity was worked out in class, the acceleration was left as a homework assignment.


time (s)
 d (m)
 velocity (m/s)
 acceleration (m/s²)



0.00
 0.00
 0.00
 0.00



3.43
 4.6
 1.34
 0.39



6.02
 9.2
 1.78
 0.17





The data demonstrated that, as I rather expected, my rate of acceleration fell as my speed increased.

The RipStik once again garnered the interest of the students, especially when I passed a camera to one of the students and asked them to be sure to get a picture of me if I fell down. The earlier image was taken by that student.


The data will be used to continue an exploration of acceleration in our next class.

Comments

  1. Mango Haiku26 January, 2010 01:15

    I -was- kept up at night wondering what your average swizzling speed was between the columns of the "B" building -- can you do a ratio between your swizzling speed and the average rate of diabetic shuffling between the same columns?

    ReplyDelete

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