3-9-09

As students walked into Physics class today, Mr. Manning welcomed us all with new grades! He passed back all papers from the past few weeks, and a new grade sheet was posted on the doors, which students anxiously checked out. The schedule for today's class is: 1. Review quiz 2. Work on a lab The answers to the quiz from last week consisted of: Next on the agenda is to finish collecting data for the Centripetal Forces Lab: Swingin' Nephews. For the last data table, we decided that we want to keep the speed constant at 9.00 m/s. The radius is .3250 m. By using the equation v=2 x pie x r/T, we found out the time for 1 rotation is .227s. Then, we multiply this number by 20 and get 4.54 s for 20 rotations. The Centripetal Force for the first trial is 4.1 N. For the next trial, the new radius is .4462 m, the new speed for 20 rotations is 6.23 s. The force is 2.75. For the third trial, the radius is .5643 m. The period is 7.88 s. The new force is 2.60 N. For the fourth trial, the new radius is .6749 m. The period is 9.42 s. The force is 2.20 N. The new radius for the next trial is .8509 m. The period is 11.88 s. The force is 1.00 N. For the last trial, the radius is .9615 m. The period is 13.43 s. The force is 1.08 N.
 * 1) b- all parts on a rotating object are the same distance away from the axis
 * 2) a- the outside
 * 3) c- they are the same
 * 4) c- meters/second
 * 5) a- tangent to the path
 * Problem 1a) f= 24 rev/s
 * Problem 1b) v=753.98 m/s

A graph for the lab!