Velocity of a rolling ball

Since spring term 2014 laboratory two has been moved to occur between the LRC and the south faculty building. This laboratory builds on the Monday linear RipStik velocity homework which was then covered on Wednesday. The Wednesday lecture included the segment speed post-to-post for the RipStik to demonstrate that the speed is changing slightly and the slope, if inspected carefully, also reflects those subtle speed changes. Wednesday also saw coverage of stationary and infinite velocity objects on time versus distance graphs. This provides a solid introduction to laboratory two. The shift away from the gym was made to permit moving into the computer laboratory at the end of this laboratory to assist the students with making a graph with five trend lines and to continue to assist the students with using Schoology. This session is particularly necessary for getting laboratory one correctly submitted. Laboratory three will be the last laboratory in the term start set to use the computer laboratory.

 Alex Etse bowls, Mark Jones times. V-Ann Nakamura, Jessica Reyes, and Marti Henry track position of the ball at one, two and three seconds.
This laboratory might be done elsewhere with tracking the time the ball passes a pre-measured location. That is the way the Monday RipStik run is done. This procedure, however, makes the distance the independent variable and the time the dependent variable. There is a convenience sample of 56 respondents to a poll posted in Schoology Science where 53 respondents note the use of the terminology independent variable/dependent variable. Three respondents chose the alternate terminology manipulated variable/responding variable. The latter terminology is clearer but less favored. One commentator noted his use of explanatory/response variable.

 Mailynda Maycry watches for the four second location, Judy Andon is monitoring the fifth second.

The college algebra text in use in the college uses the more opaque independent and dependent variable language, hence I use that language. I note that we chose the times. We were free to choose any time we wanted to choose. Our choice was an independent and free choice. The distance we measured then depended on the time we chose. We had no choice. The procedure has Mark calling out the times. V-Ann watched for where the ball WAS at one second. That word choice of  "was" seems to be important to getting a good fix on the ball location.

 Keeping the ball straight down the middle is challenging.