# Why does the period/frequency of a fan slow down significantly when I taped a piece of rubber band to it?

All of this was done with a standing fan set horizontally on a table.

During an experiment, I had to tape a piece of rubber band to one of the standing fan's blade and measured the period of the fan. Taped to the free end of the rubber band is a small metal mass, in the shape of a doughnut. The combined mass of the rubber band and the mass is 1.95 g. At this point, the fan was spinning slow enough that I could approximately count its rotation, just like if I was counting music. I approximated 31 rotations over 5 seconds, which is about 6.2 Hz. Another periodic measurement, using camera, is approximately 187fps over 3.29 seconds, though I'm not sure how to get frequency/period from this.

But when I took the rubber band off, the period/frequency of the fan increased so drastically (that is to say back to its normal period) that I could no longer hear its distinct rotation and count anything. My question is: how did taping a small rubber band with a mass of 2 g affected the period of so drastically?

I have some more data (but not sure which is useful/junk) if any more is needed to calculate anything.

• Every thrown a balance weight from the wheel of your car? Or even if you haven't, do you understand the consequences of such an event? How might that relate to the issue in front of you? Apr 19, 2015 at 20:58
• Maybe I haven't done it, but I don't understand the question. I also have never drove. Apr 19, 2015 at 21:15
• You stated "when I took the rubber band off, the period/frequency of the rubber band increased so drastically". Did you mean to say "the frequency of the fan increased so drastically"? Apr 19, 2015 at 21:24
• Yes, yes I did. That was a mistake. Damn. Apr 19, 2015 at 21:32