Since I ran out of time in class, I have to make up my own times for this lab using calculations.
The lab consists of our providing a little force by shaking this tube. Inside this tube is a string, and at one end of the string is attached a hanging mass, the other end a rubber stopper. Essentially, the hanging mass's weight is what provides the centripetal force of the rubber stopper.
However, my calculations for the time in seconds are waaay too high. I tried doing the same method for my other trials done in class and they were also far too high. I don't know what I'm doing wrong, because human error couldn't have possibly been that high all 10 trials in class.
m1 = 0.011 kg
m2 = 0.030 kg
r = 0.545 m
g = 9.81 m/s2
d = r * 2 pi * 20 (we measured the time it took for 20 revolutions)
t = d / v
W = mg
Fc = (mv2) / r
The Attempt at a Solution
Since the force we provide with our arms shouldn't factor in too much, I did:
(m2v2) / r = m1g
v = 1.400 m/s
t = d / v
t = (2pi * 0.545 * 20) / 1.4
t = 48.915 s,
which varies WAY too much with the other trials (Each trial, a variable was altered a bit, such as the hanging mass or the radius, but this change only affected the time by 3 seconds or less).
The other trials were in the 12.0 - 15.0 s range.
What am I doing wrong?