Centripetal Force Lab

Many of the lab reports have to be redone. You were supposed to see how close the known FTension which equalled Mwashers x g came to the Mstopper x ac which should have been Mstopper x omega squared x r. If they were close, you conclude that since F =Ma then our equation for ac, that is ac = omega squared x r, is correct . This was the purpose of the lab!

Many of you never made the calculations. Many of you still do not know 1 cm is .01 m and that 1 gram is .001 kg. Some of you had the stopper going around at thousands of miles per hour and some had forces exceeding 100 lbs without ever stopping to think how ridiculous your results were.

Some of you just did sloppy lab work so that for the same Mwashers and Mstoppers you got many different ac s. If you gave it a moments thought you would see that if the masses don't change and g surely doesn't change, then ac should not change.You will need to redo the lab.

Some of you were guilty of all 3 kinds of errors. You must think about what you are doing if you are to succeed at worthwhile things, and I am not just talking about this course.

Many of you described Mw x g as the force in, and M omega squared r as the force out. NOTE that the force of the string on the stopper is the force in toward the center. The force of the stopper ON THE STRING is out, but the centripetal force on the stopper is inward toward the center. If you do notunderstand this very thoroughly you must see me ASAP.