|MadSci Network: Physics|
I assume that the cylinder holding the syrup is transparent. I suppose that you could create some fancy hi-tech way of making this measurement. However, if you choose the distance properly, the time to be measured will be a convenient length of a few minutes. In that case, you can get more than enough accuracy by marking two lines on the outside of the cylinder (by using some kind of a pencil), and measuring the time by using your eyes and a watch. I suggest that you use three equally spaced lines, and measure the times that the balls reach each line. That way you can check that the balls have actually reached the terminal velocity.
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